Sony has sold more than 15 million PSPs worldwide in just one year, according to the Chicago Tribune. The iPod has sold twice that number in 2005 (32 millions iPods to be precise, and 42 millions altogether till end of 2005), but it took Apple also bit longer - they debuted the first iPod in October 2001.

So, just for now two things I wanted to blog already some time ago:
PSP Fanboy Blog
and the book from O'Reilly
PSP Hacks

See also:
PSP Feedgarden
PSP-hacks (not the same as the book)
PSP World
Sample the Web (from the author of PSP Hacks)