I think it is firmware 2.50 and higher that you can use the RSS feature on. RSS is a means of downloading things from the internet. It's weird to explain but I bet there is a
wikipedia article that will better explain it.
Regarding using instant messengers on the psp, it is possible. You need this bad boy
HERE. The program is similar to "Trillian" that is on the PC.
Of course, in order to use this, you'd need a psp with a firmware capable of using homebrew, but I'm assuming that you do.
-DarkPacMan77-