Index: models.py
===================================================================
--- models.py	(revision 792)
+++ models.py	(working copy)
@@ -125,7 +125,7 @@
 
     Username and password are required. Other fields are optional.
     """
-    username = models.CharField(_('username'), max_length=30, unique=True, help_text=_("Required. 30 characters or fewer. Alphanumeric characters only (letters, digits and underscores)."))
+    username = models.CharField(_('username'), max_length=30, unique=True, help_text=_("Required. 30 characters or fewer. Letters, numbers and @/./+/-/_ characters"))
     first_name = models.CharField(_('first name'), max_length=30, blank=True)
     last_name = models.CharField(_('last name'), max_length=30, blank=True)
     email = models.EmailField(_('e-mail address'), blank=True)
Index: forms.py
===================================================================
--- forms.py	(revision 792)
+++ forms.py	(working copy)
@@ -11,9 +11,9 @@
     """
     A form that creates a user, with no privileges, from the given username and password.
     """
-    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^\w+$',
-        help_text = _("Required. 30 characters or fewer. Alphanumeric characters only (letters, digits and underscores)."),
-        error_message = _("This value must contain only letters, numbers and underscores."))
+    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^[\w.@+-]+$',
+        help_text = _("Required. 30 characters or fewer. Letters, digits and @/./+/-/_ only."),
+        error_message = _("This value may contain only letters, numbers and @/./+/-/_ characters."))
     password1 = forms.CharField(label=_("Password"), widget=forms.PasswordInput)
     password2 = forms.CharField(label=_("Password confirmation"), widget=forms.PasswordInput)
 
@@ -44,9 +44,9 @@
         return user
 
 class UserChangeForm(forms.ModelForm):
-    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^\w+$',
-        help_text = _("Required. 30 characters or fewer. Alphanumeric characters only (letters, digits and underscores)."),
-        error_message = _("This value must contain only letters, numbers and underscores."))
+    username = forms.RegexField(label=_("Username"), max_length=30, regex=r'^[\w.@+-]+$',
+        help_text = _("Required. 30 characters or fewer. Letters, digits and @/./+/-/_ only."),
+        error_message = _("This value may contain only letters, numbers and @/./+/-/_ characters."))
     
     class Meta:
         model = User