One nice feature that the Powerbook has over the iBook is support for screen spanning: you can connect an external monitor to the laptop and ‘extend’ the desktop to the new monitor. For some inexplicable reason (save maybe another ‘selling point’ of the Powerbook), iBooks don’t ship with this feature. Instead, they only support screen ‘mirroring’, which is pretty worthless since the laptop goes to sleep with the lid closed.
Here‘s a simple hack to enable screen spanning on most recent iBooks. Just run the installer script, and it works. I’ve had no problems, but of course some people have complained that the hack broke their iBook, killed their dog, and ran away with their mothers.