Index: Python/bltinmodule.c
===================================================================
--- Python/bltinmodule.c	(revision 55704)
+++ Python/bltinmodule.c	(working copy)
@@ -1142,17 +1142,14 @@
 static PyObject *
 builtin_intern(PyObject *self, PyObject *args)
 {
-	PyObject *s;
-	if (!PyArg_ParseTuple(args, "S:intern", &s))
+	PyObject *internfunc;
+	if (Py_Py3kWarningFlag &&
+	    PyErr_Warn(PyExc_DeprecationWarning, 
+		       "intern() is moving to sys.intern() in 3.x") < 0)
 		return NULL;
-	if (!PyString_CheckExact(s)) {
-		PyErr_SetString(PyExc_TypeError,
-				"can't intern subclass of string");
-		return NULL;
-	}
-	Py_INCREF(s);
-	PyString_InternInPlace(&s);
-	return s;
+
+	internfunc = PySys_GetObject("intern");
+        return PyEval_CallObject(internfunc, args);
 }
 
 PyDoc_STRVAR(intern_doc,
Index: Python/sysmodule.c
===================================================================
--- Python/sysmodule.c	(revision 55704)
+++ Python/sysmodule.c	(working copy)
@@ -578,6 +578,31 @@
 );
 #endif
 
+static PyObject *
+sys_intern(PyObject *self, PyObject *args)
+{
+        PyObject *s;
+        if (!PyArg_ParseTuple(args, "S:intern", &s))
+                return NULL;
+        if (!PyString_CheckExact(s)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "can't intern subclass of string");
+                return NULL;
+        }
+        Py_INCREF(s);
+        PyString_InternInPlace(&s);
+        return s;
+}
+
+PyDoc_STRVAR(intern_doc,
+"intern(string) -> string\n\
+\n\
+``Intern'' the given string.  This enters the string in the (global)\n\
+table of interned strings whose purpose is to speed up dictionary lookups.\n\
+Return the string itself or the previously interned string object with the\n\
+same value.");
+
+
 #ifdef USE_MALLOPT
 /* Link with -lmalloc (or -lmpc) on an SGI */
 #include <malloc.h>
@@ -776,6 +801,7 @@
 	{"getwindowsversion", (PyCFunction)sys_getwindowsversion, METH_NOARGS,
 	 getwindowsversion_doc},
 #endif /* MS_WINDOWS */
+        {"intern",      sys_intern,     METH_VARARGS, intern_doc},
 #ifdef USE_MALLOPT
 	{"mdebug",	sys_mdebug, METH_VARARGS},
 #endif
Index: Doc/lib/libsys.tex
===================================================================
--- Doc/lib/libsys.tex	(revision 55704)
+++ Doc/lib/libsys.tex	(working copy)
@@ -340,6 +340,22 @@
   \versionadded{1.5.2}
 \end{datadesc}
 
+\begin{funcdesc}{intern}{string}
+  Enter \var{string} in the table of ``interned'' strings and return
+  the interned string -- which is \var{string} itself or a copy.
+  Interning strings is useful to gain a little performance on
+  dictionary lookup -- if the keys in a dictionary are interned, and
+  the lookup key is interned, the key comparisons (after hashing) can
+  be done by a pointer compare instead of a string compare.  Normally,
+  the names used in Python programs are automatically interned, and
+  the dictionaries used to hold module, class or instance attributes
+  have interned keys.  \versionchanged[Interned strings are not
+  immortal (like they used to be in Python 2.2 and before);
+  you must keep a reference to the return value of \function{intern()}
+  around to benefit from it]{2.3} \versionchanged{intern was moved to sys 
+  in Python 2.6 - it will disappear from the builtin module in 3.0}{2.6}
+\end{funcdesc}
+
 \begin{datadesc}{last_type}
 \dataline{last_value}
 \dataline{last_traceback}