ITmedia has put up the first impression review for PSP (PlayStation Portable). It supports various features like MP3 player, MPEG4 viewer, Wireless LAN and USB mass storage.
There've been already many PSP hacking projects going on. iTunes with PSP (sync your iTunes MP3 playlist to PSP mass storage like iPod), Movie converter for PSP and Internet Proxy Software for Wireless LAN gaming (enables your game battle with someone over the internet using tunneling). Maybe it's time for "PSP Hacks".