if you spot a dead link or know an interesting site which is missing, please let us know :)
pspdev.ofcode.com kernel api documentation
www.oopo.net toolchain build script
nil.rpc1.org interface to the remote control rs232 port
wiki.pspdev.org pspdev wiki
forums.ps2dev.org ps2dev forums
www.devkit.tk precompiled gcc for windows
www.deadcoderssociety.tk precompiled gcc for osx
www.aibohack.com
Memorystick Pinout
www.memorystick.org developer site, requires registration
www.psp-development.com; some pictures of the PSP internals
Marcus Comstedt one of the first PSP related websites
Loser precompiled toolchains for win32
PSPSDK Documentation online version of the doxygen generated Documentation
PSP Hardware Hack Project 0okm's Blog
Moonlight's Page Silverspring's Page PSP PRX Libraries Documentation Project.
uClinux on the PSP a Linux Porting Effort.
MrMrIce VFPU Info
Eurasia WIKI Links to misc Info
F-Secure bricks a PSP on camera "security advisory" by F-Secure, showing the 2.0 Hello World in action :)