Looking for a good iphone instant messaging client

With my new job I have to instant message clients on a variety of platforms, aim, google, msn, yahoo, ichat (mobileme), icq, and myspace.
What are some good iphone apps to look at for this? If necessary I will pay for one but if there are free options available that are good I'd like to look at that.
Thank you for your help.

Beejive is the one I am currently using. Has push notifications. Signs into all those and keeps you signed. I have been waiting for meeboo for about 2 years now but still nothing... Beejive costs 9.99

I am using eBuddy at the moment. It's free and I have had no problems with it yet. It connects with quite a few instant messaging clients.