diff --git a/scrapy/contrib_exp/newitem/__init__.py b/scrapy/contrib_exp/newitem/__init__.py
index a4c3e81df..bde80fc7e 100644
--- a/scrapy/contrib_exp/newitem/__init__.py
+++ b/scrapy/contrib_exp/newitem/__init__.py
@@ -1,2 +1 @@
 from scrapy.contrib_exp.newitem.models import Item
-from scrapy.contrib_exp.newitem.fields import *
diff --git a/scrapy/contrib_exp/newitem/fields.py b/scrapy/contrib_exp/newitem/fields.py
index 49d79a481..15773d3ab 100644
--- a/scrapy/contrib_exp/newitem/fields.py
+++ b/scrapy/contrib_exp/newitem/fields.py
@@ -3,18 +3,10 @@ import decimal
 import re
 import time
 
-
-__all__ = ['MultiValuedField', 'BooleanField', 'DateField', 'DateTimeField',
-           'DecimalField', 'FloatField', 'IntegerField', 'StringField']
-
-
 class BaseField(object):
     def __init__(self, default=None):
         self.default = default or self.to_python(None)
 
-    def assign(self, value):
-        return self.to_python(value)
-
     def to_python(self, value):
         """
         Converts the input value into the expected Python data type.
@@ -23,18 +15,6 @@ class BaseField(object):
         return value
 
 
-class Field(BaseField):
-    def assign(self, value):
-        if hasattr(value, '__iter__'):
-            return self.to_python(self.deiter(value))
-        else:
-            return self.to_python(value)
-
-    def deiter(self, value):
-        "Converts the input iterable into a single value."
-        return ' '.join(value)
-
-
 class MultiValuedField(BaseField):
     def __init__(self, field_type, default=None):
         self._field = field_type()
@@ -47,15 +27,14 @@ class MultiValuedField(BaseField):
             return [self._field.to_python(v) for v in value]
 
 
-class BooleanField(Field):
+class BooleanField(BaseField):
     def to_python(self, value):
         return bool(value)
 
 
-ansi_date_re = re.compile(r'^\d{4}-\d{1,2}-\d{1,2}$')
+class DateField(BaseField):
+    ansi_date_re = re.compile(r'^\d{4}-\d{1,2}-\d{1,2}$')
 
-
-class DateField(Field):
     def to_python(self, value):
         if value is None:
             return value
@@ -64,7 +43,7 @@ class DateField(Field):
         if isinstance(value, datetime.date):
             return value
 
-        if not ansi_date_re.search(value):
+        if not self.ansi_date_re.search(value):
             raise ValueError("Enter a valid date in YYYY-MM-DD format.")
 
         year, month, day = map(int, value.split('-'))
@@ -74,7 +53,7 @@ class DateField(Field):
             raise ValueError("Invalid date: %s" % str(e))
 
 
-class DateTimeField(Field):
+class DateTimeField(BaseField):
     def to_python(self, value):
         if value is None:
             return value
@@ -111,41 +90,34 @@ class DateTimeField(Field):
                     raise ValueError('Enter a valid date/time in YYYY-MM-DD HH:MM[:ss[.uuuuuu]] format.')
 
 
-class DecimalField(Field):
+class DecimalField(BaseField):
     def to_python(self, value):
-        if value is None:
-            return value
-        try:
-            return decimal.Decimal(value)
-        except decimal.InvalidOperation:
-            raise ValueError("This value must be a decimal number.")
+        return decimal.Decimal(value) if value is not None else None
 
 
-class FloatField(Field):
+class FloatField(BaseField):
     def to_python(self, value):
-        if value is None:
-            return value
-        try:
-            return float(value)
-        except (TypeError, ValueError):
-            raise ValueError("This value must be a float.")
+        return float(value) if value is not None else None
 
 
-class IntegerField(Field):
+class IntegerField(BaseField):
     def to_python(self, value):
-        if value is None:
-            return value
-        try:
-            return int(value)
-        except (TypeError, ValueError):
-            raise ValueError("This value must be an integer.")
+        return int(value) if value is not None else None
 
 
-class StringField(Field):
+class StringField(BaseField):
     def to_python(self, value):
-        if isinstance(value, basestring):
+        if hasattr(value, '__iter__'):
+            return self.to_python(self.to_single(value))
+        elif isinstance(value, basestring):
             return value
-        if value is None:
+        elif value is None:
             return value
-        raise ValueError("This field must be a string.")
+        else:
+            raise ValueError("StringField expects a basestring, got %s" \
+                % type(value).__name__)
+
+    def to_single(self, value):
+        "Converts the input iterable into a single value."
+        return ' '.join(value)
 
diff --git a/scrapy/contrib_exp/newitem/models.py b/scrapy/contrib_exp/newitem/models.py
index b29a3a854..b84de9b1a 100644
--- a/scrapy/contrib_exp/newitem/models.py
+++ b/scrapy/contrib_exp/newitem/models.py
@@ -2,40 +2,45 @@ from scrapy.item import ScrapedItem
 from scrapy.contrib_exp.newitem.fields import BaseField
 
 
-class ItemMeta(type):
+class _ItemMeta(type):
 
     def __new__(meta, class_name, bases, attrs):
         cls = type.__new__(meta, class_name, bases, attrs)
         cls.fields = cls.fields.copy()
-        for n, v in attrs.items():
+        for n, v in attrs.iteritems():
             if isinstance(v, BaseField):
                 cls.fields[n] = v
-
         return cls
 
 
 class Item(ScrapedItem):
     """ This is the base class for all scraped items. """
 
-    __metaclass__ = ItemMeta
+    __metaclass__ = _ItemMeta
 
     fields = {}
 
-    def __init__(self):
+    def __init__(self, values=None):
         self._values = {}
+        if isinstance(values, dict):
+            for k, v in values.iteritems():
+                setattr(self, k, v)
+        elif values is not None:
+            raise TypeError("Items must be instantiated with dicts, got %s" % \
+                type(values).__name__)
 
     def __setattr__(self, name, value):
         if name.startswith('_'):
-            return object.__setattr__(self, name, value)
+            return ScrapedItem.__setattr__(self, name, value)
 
         if name in self.fields.keys():
-            self._values[name] = self.fields[name].assign(value)
+            self._values[name] = self.fields[name].to_python(value)
         else:
             raise AttributeError(name)
 
     def __getattribute__(self, name):
         if name.startswith('_') or name == 'fields':
-            return object.__getattribute__(self, name)
+            return ScrapedItem.__getattribute__(self, name)
         
         if name in self.fields.keys():
             try:
@@ -46,9 +51,8 @@ class Item(ScrapedItem):
             raise AttributeError(name)
 
     def __repr__(self):
+        """Generate a representation of this item that can be used to
+        reconstruct the item by evaluating it
         """
-        Generate the following format so that items can be deserialized
-        easily: ClassName({'attrib': value, ...})
-        """
-        reprdict = dict((field, getattr(self, field)) for field in self.fields)
-        return "%s(%s)" % (self.__class__.__name__, repr(reprdict))
+        values = dict((field, getattr(self, field)) for field in self.fields)
+        return "%s(%s)" % (self.__class__.__name__, repr(values))
diff --git a/scrapy/tests/test_itemadaptor.py b/scrapy/tests/test_itemadaptor.py
index c6d606e7b..4bc3e5308 100644
--- a/scrapy/tests/test_itemadaptor.py
+++ b/scrapy/tests/test_itemadaptor.py
@@ -1,16 +1,16 @@
 import unittest
 import string
 from scrapy.contrib_exp.newitem.adaptors import adaptor, ItemAdaptor
-from scrapy.contrib_exp.newitem import * 
+from scrapy.contrib_exp.newitem import Item, fields
 
 
 class BaseItem(Item):
-    name = StringField()
+    name = fields.StringField()
 
 
 class TestItem(BaseItem):
-    url = StringField()
-    summary = StringField()
+    url = fields.StringField()
+    summary = fields.StringField()
 
 
 class BaseAdaptor(ItemAdaptor):
@@ -30,7 +30,7 @@ class InheritDefaultAdaptor(DefaultedAdaptor):
 
 
 class MultiValuedTestItem(Item):
-    names = MultiValuedField(StringField)
+    names = fields.MultiValuedField(fields.StringField)
 
 
 class MultiValuedItemAdaptor(ItemAdaptor):
diff --git a/scrapy/tests/test_newitem.py b/scrapy/tests/test_newitem.py
index 4d6278b88..68b72087d 100644
--- a/scrapy/tests/test_newitem.py
+++ b/scrapy/tests/test_newitem.py
@@ -2,7 +2,7 @@ import datetime
 import decimal
 import unittest
 
-from scrapy.contrib_exp.newitem import *
+from scrapy.contrib_exp.newitem import Item, fields
 from scrapy.contrib_exp.newitem.fields import BaseField
 
 
@@ -10,16 +10,30 @@ class NewItemTest(unittest.TestCase):
 
     def test_simple(self):
         class TestItem(Item):
-            name = StringField()
+            name = fields.StringField()
 
         i = TestItem()
         i.name = 'name'
         assert i.name == 'name'
 
+    def test_init(self):
+        class TestItem(Item):
+            name = fields.StringField()
+        
+        i = TestItem()
+        assert i.name is None
+
+        i2 = TestItem({'name': 'john doe'})
+        assert i2.name == 'john doe'
+
+        self.assertRaises(TypeError, TestItem, name='john doe')
+
+        self.assertRaises(AttributeError, TestItem, {'name': 'john doe', 'other': 'foo'})
+
     def test_multi(self):
         class TestMultiItem(Item):
-            name = StringField()
-            names = MultiValuedField(StringField)
+            name = fields.StringField()
+            names = fields.MultiValuedField(fields.StringField)
 
         i = TestMultiItem()
         i.name = 'name'
@@ -43,14 +57,14 @@ class NewItemTest(unittest.TestCase):
 
     def test_default_value(self):
         class TestItem(Item):
-            name = StringField(default='John')
+            name = fields.StringField(default='John')
  
         i = TestItem()
         assert i.name == 'John'
 
-    def test_topython_iter(self):
+    def test_to_python_iter(self):
         class TestItem(Item):
-            name = StringField()
+            name = fields.StringField()
  
         i = TestItem()
         i.name = ('John', 'Doe')
@@ -58,25 +72,31 @@ class NewItemTest(unittest.TestCase):
 
     def test_repr(self):
         class TestItem(Item):
-            name = StringField()
+            name = fields.StringField()
+            number = fields.IntegerField()
 
         i = TestItem()
         i.name = 'John Doe'
-        assert i.__repr__() == "TestItem({'name': 'John Doe'})"
+        i.number = '123'
+        itemrepr = repr(i)
+        assert itemrepr == "TestItem({'name': 'John Doe', 'number': 123})"
+
+        i2 = eval(itemrepr)
+        assert i2.name == 'John Doe'
+        assert i2.number == 123
 
 
 class NewItemFieldsTest(unittest.TestCase):
     
     def test_base_field(self):
-        f = BaseField()
+        f = fields.BaseField()
 
         assert f.default == None
-        assert f.assign(1) == 1
         assert f.to_python(1) == 1
 
     def test_boolean_field(self):
         class TestItem(Item):
-            field = BooleanField()
+            field = fields.BooleanField()
 
         i = TestItem()
 
@@ -94,7 +114,7 @@ class NewItemFieldsTest(unittest.TestCase):
 
     def test_date_field(self):
         class TestItem(Item):
-            field = DateField()
+            field = fields.DateField()
 
         i = TestItem()
 
@@ -121,7 +141,7 @@ class NewItemFieldsTest(unittest.TestCase):
 
     def test_datetime_field(self):
         class TestItem(Item):
-            field = DateTimeField()
+            field = fields.DateTimeField()
 
         i = TestItem()
 
@@ -163,7 +183,7 @@ class NewItemFieldsTest(unittest.TestCase):
 
     def test_decimal_field(self):
         class TestItem(Item):
-            field = DecimalField()
+            field = fields.DecimalField()
 
         i = TestItem()
 
@@ -176,11 +196,11 @@ class NewItemFieldsTest(unittest.TestCase):
         def set_invalid_value():
             i.field = 'text'
 
-        self.assertRaises(ValueError, set_invalid_value)
+        self.assertRaises(decimal.InvalidOperation, set_invalid_value)
 
     def test_float_field(self):
         class TestItem(Item):
-            field = FloatField()
+            field = fields.FloatField()
 
         i = TestItem()
 
@@ -197,7 +217,7 @@ class NewItemFieldsTest(unittest.TestCase):
 
     def test_integer_field(self):
         class TestItem(Item):
-            field = IntegerField()
+            field = fields.IntegerField()
 
         i = TestItem()
 
@@ -214,7 +234,7 @@ class NewItemFieldsTest(unittest.TestCase):
 
     def test_string_field(self):
         class TestItem(Item):
-            field = StringField()
+            field = fields.StringField()
 
         i = TestItem()