This Is The Best D&D Thing Ever
iplay4e is a new service that stores your D&D characters from the Character Builder online. It also has a mode for you to use at the table, with full HP / power useage and whatnot tracking. It's all browser based, and optimized to work with iPhone /iPod Touch. And every power links to it's full dndi entry, incase you need more reference. You need a subscription to dndi to really get the fullest out of it, but you'll also never need to buy a physical copy of any of the sourcebooks.