First buy an HP Touchpad and a Touchstone Inductive Charging Dock (about $200 for both).
Then select a good location and mounting height to suit all users of the tablet.
Then use the Touchstone Dock as a template to trace the area to cut on the wall. Use a stud finder to make sure you are in an open wall bay.
Then cut your hole with a drywall saw (being careful of wires in wall, it might be a good idea to shut off power to be safe).
Now test fit the charger and adjust hole accordingly. You'll want a snug fit to prevent drywall cracks later.
Leave the factory plastic on the Touchstone and cover the front of it in painters tape to give the drywall mud something to stick to.
Just add a single layer of tape, butting edges together to keep it flat and smooth.
Test fit again since the tape adds thickness you might need to saw the hole slightly larger.
I took the end of an extension cord and wired it to power from the switchbox below to accept the plug-in charger for the Touchstone. I had a switchbox on the opposite side of this wall that could house the charger and keep it accessible for safety and servicing. DO NOT LEAVE IT FLOATING IN THE WALL!
Add a wood backer strip with a couple of dry wall screws, a 1x2 or a paint stirring stick will work.