http://www.bowob.com seems to replicate the look the best, but it doesn't seem that stable or customizable

http://www.cometchat.com looks decent

http://bar.meebo.com requires people to sign in with their IM accounts - I want people to simply be chatting because they're logged into my site (they are logged in with full names)

I heard facebook was going to realize the "facebook chat bar" as a widget/social plugin - any word on this?

Any help would be much appreciate - thank you!