Index: django/template/defaultfilters.py
===================================================================
--- django/template/defaultfilters.py	(revision 11450)
+++ django/template/defaultfilters.py	(working copy)
@@ -862,11 +862,30 @@
         return u"Error in formatting: %s" % force_unicode(e, errors="replace")
 pprint.is_safe = True
 
+def concat(value, arg, autoescape=None):
+    """
+    Concats value with arg.
+    
+    For example: {{ "this is"|concat:" a concatenated string." }}
+    """
+    value = force_unicode(value)
+    if autoescape:
+        from django.utils.html import conditional_escape
+        value = conditional_escape(value)
+    try:
+        data = value + arg
+    except AttributeError: # fail silently but nicely
+        return value
+    return mark_safe(data)
+concat.is_safe = True
+concat.needs_autoescape = True
+
 # Syntax: register.filter(name of filter, callback)
 register.filter(add)
 register.filter(addslashes)
 register.filter(capfirst)
 register.filter(center)
+register.filter(concat)
 register.filter(cut)
 register.filter(date)
 register.filter(default)