Try this unblocker!

It's new and nobody knows about it yet:
http://tiredstudents.com/

It looks like a lot of school administrator type people have been watching our sources, and are blocking new unblockers pretty much as soon as they're released. So all the unblockers we've posted on this site are probably blocked and any new ones we post from that same source will be blocked very quickly as well. For this reason it'd be best if you try to make your own unblocker instead - you can find instructions on how to do this here: How To Make A Proxy

How to unblock AIM at school

You've found that AIM is being blocked? How terrible! Fortunately, it is possible to bypass the school filter and access AIM anyway.

 The simplest way to get access to AIM at school is by using an unblocker. You can access all other blocked sites by using this method. You'll find lists of unblockers right at the end of this page.

 What do unblockers do?

 An unblocker is like a gateway that pass information between your computer and the site you're visiting. The unblocker goes to the site you want on your behalf, downloads the page, and forwards it to you. So the site you want to access never sees your IP. So in effect you are surfing sites in an indirect way. School filters think you are just visiting the unblocker, not the site you actually want.

 A little advice when using an unblocker for AIM

 It's best to use an unblocking site that hardly anyone knows about. Unblockers that get used a lot will be found and blocked by the school. Unblockers that you find by doing a search will be filtered sooner because they're so obvious. Even if you find a good one it's always wise to have an alternative you can try if your main one gets blocked.

 Another method to unblock AIM at school is to set up your own unblocker tool. This is harder than just using an unblocker but better in the long run because if they block it, you can make another. Explaining how to do this is not in this guide, if you search for "How to make your own proxy" you should find help. You can even make some money from this if you put ads on it.

 Other ways to unblock AIM are by using sites that translate pages, for example Google Translate or Babelfish. Also try Google's cached copy of the site. Unfortunately, it's not possible to log in using these methods, so it's still better to use unblockers for AIM, however these tricks are great for most other sites.

More info: How to unblock AIM