apt-transport-tor 0.2.1 should now be on your preferred unstable Debian mirror. It will let you download Debian packages through Tor. New in this release: support for HTTPS over Tor, to keep up with people.debian.org. :)
I haven't mentioned it before on this blog. To get it working, you need to "apt-get install apt-transport-tor", and then use sources.list lines like so:
deb tor+http://http.debian.net/debian unstable main Note the use of http.