Someone has gone through a lot of trouble to make a Google Maps mash-up of the Magic Kingdom. View it with the Satellite option for the most fun. It has every restaurant, restroom, and attraction highlighted on it. If you could get a bit more data on each item and then get this on your mobile phone/blackberry/etc, you wouldn’t have to port around that guidebook anymore.
This appears to have been made by a company called RETLAW. However after some initial research, I don’t think that’s the same company that Walt Disney set up to manage his family finances. (Thanks to John C!)