One of the coolest things I have found for Walt Disney World planning is the applications that are available for you if you have a cellphone that can access the web or a PDA. 

PocketDisney has several things that are very useful including a countdown clock for you desktop, maps and park info for download to your PDA, and a toolbar for your browser.

eGuides to Go has a condensed guide to WDW, a live entertainment guide, and menus for iSilo (for Palm, PocketPC, Windows CE and Handheld PC OS), and Plucker format for Palm OS devices.  They also have a version for iPods that have the Notes function.

And finally, for those using TouringPlans.com, you can download those plans to your PDA or SmartPhone using GnoMobile.com.