An even easier method of doing this is using the built-in SOCKS proxy in OpenSSH. Simply add "DynamicForward 3000" to your ssh_config file (or use the -D switch of the ssh command). After you connect, a locally accessible SOCKS proxy is then available on localhost port 3000, all nicely tunneled through the server. Set Firefox/Gaim/etc to use this port (be sure to use the SOCKS proxy settings and not HTTP) and you're set.