Proxying applications through firewalls to bounce your connection around is pretty much a must for anyone trying to get around IP based content restrictions or to bypass content restrictive firewalls. This happens a lot in work environments, and is super useful for people out in the field who are on untrusted networks or networks that otherwise cripple your access. id just wrote an article on how to bypass content restrictions based on tunneling connections over SSH.
I wrote a similar article on how to tunnel Trillian Pro that is wildly out of date given that I wrote it two years ago. His is much better and applies to a lot more applications, so read his instead. For anyone who needs to bounce their connection from different IP addresses this is a must read.