[Shohan]

Right now OctroTalk, Slick, and Palringo are free from their developers. I think they're still in the testing phase so that might change, but I'm not sure.

OctroTalk worked good for me in the beginning, but recently I've been having issues connecting to Yahoo through it. It's pretty clean and no-frills, but does the job good. Tabbed conversation windows and a Today Screen plugin.

Slick is pretty nice, but I had an issue with the slick window going black if S2U2 came up while the Slick window was active. Not sure how to fix that. I didn't care for Slick much, though it works well and does what it advertises. Slick doesn't have a Today plugin.

Palringo is my favorite so far. Nice interface and connects to all the services. Tabbed conversations and a today plugin. My only issue is that it seems to disconnect at random for me which is annoying. This could be due to coverage in my area, however, though I never noticed the problem with other IM apps.