Jake over at 8BitJoystick has posted about a new book he contributed to called PSP Hacks : Tips & Tools for Your Mobile Gaming and Entertainment Handheld (Hacks). This is a paperback book that focuses soley on the PSP and hacks for it.
Some of the hacks included are surfing the Web with a PSP, chat in IRC, and use the PSP to read web comics, ebooks, and RSS feeds. Other expert tips and tools allow you to sync an address book to your PSP, watch UMD movies, fool iTunes into thinking the PSP is an iPod Shuffle, and much more.
Sounds like a great book for both advanced and new PSP users. I for one will be checking it out as soon as I can.