I am looking for a IM Zimlet for the Web-Client of Zimbra. There is Meebo, which I will probably try out, but I do not like that fact that all my users have to create a Meebo account. I would be nice if there was a built in IM for Zimbra.

1) Does Meebo function with 7.2 of Zimbra?
2) Is there a IM built against the accounts already setup in Zimbra, instead of having to create new accounts for the IM chosen?
3) Any other IM Zimlets I should check out?