I've got a WM5 based PocketPC device which comes with a pretty good IM client as part of PocketMSN. It's good but not perfect. It's a lot better than the IM client I was using on my Z600 3G phone back in Aus it relied on SMS messages and Java).

Now however there's a much better solution for any user with phone that has a browser installed.

Currently in Beta the Windows Live Messenger for mobile devices is quick, simple and easy to use on pretty much any browser (including Safari where I had a quick play just to see how it behaved - IMO better than WebMessenger!)

Just like the Windows Live Search for Mobile it would appear that the folks in the various Microsoft labs are really doing a good job of encompassing the web in a very open way.

I can't wait to see what's next!