I have a 12" Powerbook, and recently picked up a ProView LCD display. It has a widescreen resolution of 1280x800, however, OSX only seems to support 1280 x 768. Small difference, granted, but is there a way to tweak this?
It may not support PowerBooks, but I don't see why it wouldn't. Just be careful not to switch your laptop's built-in LCD to something unsupported, as I think getting the LCD back to a normal resolution is a pain in OS X.