If I may complain for a second: PowerBooks simply do not work well as desktop replacements— that is, as a laptop that gets used at least half the time with the lid closed, attached to an external monitor, mouse, keyboard, printer, speakers and what have you. Without a port replicator, everything must be plugged in when going from laptop to desktop, and unplugged when going from desktop to laptop. And before you say "Bluetooth keyboard and mouse," note that a USB keyboard is required to run with the lid closed. Transitioning to desktop mode requires the PowerBook to be booted up, properly asleep (and breathing), and closed before plugging everything in.
But what really earns PowerBooks the raspberry on this one is the transition back to laptop mode: Once put to sleep, unplugging either a USB device or the video cable will wake it up. If you unplug a USB device (such as the keyboard or mouse) first, video will return to the external monitor and you'll have to plug the device back in to do anything further. If you unplug the video cable first, the PowerBook will wake up, realize the lid is closed and there's no external video, then die an improper death. Now that you've lost whatever you had open and any unsaved documents are toast, you might as well proceed to unplug everything, open the lid, turn it on and wait a few minutes for it to start up. But you can't plug the video back in and expect to do it in desktop mode: It's dead, not sleeping, and cannot be awakened without its power button, under the lid.
In short, there is no way to go from laptop mode to desktop mode without being on and asleep, and there's no clean way to go from desktop mode to laptop mode without being completely shut down. Someone please correct me if I'm wrong, because this just ain't right.
To get back into laptop mode, I unplug everything, then sleep the laptop.
When it wakes up, it re-detects displays, finds no external, and you're good to go.
I agree this needs to be dealt with better. It's a big pain.