DSLR Controller is a new app (currently in Beta) to allow you to access and operate your Canon HDSLR from your Android phone or tablet. Setup seems to be pretty simple, besides the app you will need a USB host cable. The one downside is that the app has pretty demanding specs. It requires a dual core Android device, which covers most of the tablets out there but only a handful of phones. Still, if you have a compatible device, this may be a very handy app to have around.
Android Market link.