Meebo just announced a nifty little Firefox Extension that can be configured to auto-sign in to your meebo account whenever you start Firefox, and run your buddy list in the sidebar.

Meebo is a website that allows you to sign in to all the various Instant Messaging (live, aim, yahoo, google talk, icq) services using a web browser. Having a meebo account lets you store your accounts on their server, making it very simple to sign in to any service from anywhere. This plugin makes it a little more convenient to see them all at once (not sure though about voice or video options, sorry). A bonus is for me is that with meebo I can sign in to multiple live accounts at the same time.