Here is an answer to Yahoo Messenger and MSN Messenger from Google. It is Google Talk (http://www.google.com/talk). It unites net telephony with an instant messaging network and builds on the Gmail e-mail service.
Here are some comments on it from my friends:
> Initial reports say that it is awesome. We have to wait and watch until it catches on and the bandwidth runs out :-)
It is really awesome man. We've been testing it internally for sometime now. The audio clarity is simply astounding. It is based on Jabber which is an open protocol. Any Jabber client can be used to connect to the Talk service.
Oh, and Google will never run out of bandwidth :-)
> Maybe google has a trick up their sleeve for effective utilization of bandwidth. It would be interesting to see what that is. I don't know what tricks they do internally, but they do spend a lot of effort on compression, optimization and the best use of bandwidth. The best part is the client which is just a 900K download.