AIMOnPSP is an AOL Instant Messenger client for the Sony Playstation Portable. This is a free, web based AIM client which can be accessed from any Javascript browser, including the one on the latest firmware for PSP and any other mobile phone browser. But there are some concerns about this service:

1) Disclosing your AOL password to a third party service
2) They don’t use SSL to send your password [SSL information]

But anyway that’s your choice. Even mail2web asks for your POP3 password so its all about trust.

AIMOnPSP Homepage