set the zip_safe flag to False

This means that by default the allmydata-tahoe egg will be a directory with a tree of files instead of a zip file containing files.  I prefer the former because it makes it easier for people to hack into it.
Unfortunately the files therein are still going to be .pyc's instead of .py's, if I understand correctly.  I would prefer for them to be .py's.  See also discussion on the distutils-sig mailing list:

http://mail.python.org/pipermail/distutils-sig/2007-July/007827.html

setup.py

@@ -133,4 +133,5 @@ setup(name='allmydata-tahoe',
 #          Extension("allmydata.Crypto.PublicKey._fastmath",
 #                    sources=["src/allmydata/Crypto/_fastmath.c"]),
           ],
+      zip_safe=False, # We prefer unzipped for easier access.
       )