I have found out how to use IM on kindle (yes, I know it is taking it too far, but why not
hey, the browsing it free!)
You have to use the mobile version of meebo, which is at
https://www.meebo.com/mobile
The first login will
not work. I don't know why, but it does that on every device (you can try it with your desktop browser, too). Logoff with the X button, login
again - voilla, you have your IM buddy list and you can chat.
I haven't tested it very much yet, but I think you may like it