> Are you familiar with Python's tarfile module?

yes, but the tarfile module won't decompress .Z (unix 'compress'-ed files) expicity or transparently, and zlib (or gzip, I forget which) won't work on a URL stream (no .seek and/or .tell).

I could put a wrapper around zlib to make it work with the URL stream, but in the end I figured this was much simpler.