I just implemented a GZipMiddleware for Django, so now you can enjoy the bandwidth-saving goodness that is gzip without using django.middleware.cache (actually, since Djangos cache-middleware is oblivious to the Vary header, it will not work with GZipMiddleware...)
It is in ibofobi.middleware.gzip under
http://mel.ibofobi.dk/~sune/r/ibofobi.git. Enjoy.