The foXnoMad favorite Meebo, lets you get around instant messaging blocks at school or work. Meebo encrypts your passwords when you sign on (unlike AIM or MSN) and saves conversations for later review or in the event you lose touch with the Internet. Now Meebo has an SSL page that will encrypt your messages too, in case you want a little more privacy.
So bookmark the encrypted page while it is around. Using Meebo doesn’t require you to sign up for anything, just enter in your existing AIM, MSN, Yahoo, etc. account and password on their main page. Creating a Meebo account does give you some small perks however, like a buddy icon (aww, how cute).