IM Privacy: OTR
There is a tool that I recommend to absolutely everyone - Off-The-Record Messaging, aka OTR which works with GAIM… err, Pidgin. Mac users can’t use Pidgin, but they get the even-better Adium which uses the same code for connections, has a much friendlier interface, and has OTR built-in. In the Adium preferences there is a pref to encrypt conversation automatically. Recommended!
If you’re IMming with me and you see a message that tells you to get OTR, that’s it working to keep the rest of the internet out of our conversation! :)