diff -r 47134672d506 Lib/threading.py
--- a/Lib/threading.py  Wed Nov 02 09:47:06 2011 +0000
+++ b/Lib/threading.py  Sun Nov 06 23:38:33 2011 +0100
@@ -159,8 +159,7 @@
         self._target = target
         self._args = args
         self._kwargs = kwargs
-        if name:
-            self._thread.setName(str(name))
+        self._thread.setName(str(name or _newname()))

     def _create_thread(self):
         return _newFunctionThread(self.__bootstrap, ())
@@ -267,6 +266,13 @@
 def enumerate():
     return _threads.values()

+# Helper to generate new thread names
+_counter = 0
+def _newname(template="Thread-%d"):
+    global _counter
+    _counter = _counter + 1
+    return template % _counter
+
 from thread import stack_size