A new version is out for Adhoc Messenger from FaT3oYCG. Adhoc Messenger is a homebrew program that allows you to send and receive messages between PSP units via an Adhoc connection. Now on version 2.0, the program now has several new features.
You can check out the previous release of the homebrew for a video of the program in action
If you've ever had the urge to just chat with a friend using your Sony PlayStation Portable without using the internet, then this application from PSP homebrew developer FaT30YCG might interest you. The Adhoc Messenger v1.0 allows users to send and recieve messages on their PSP via an Adhoc connection