onSale had/have the HP Bluetooth TouchPad Wireless Keyboard for $24.99 + shipping. Had it paired up under a minute and using it in the car.
With a Targus Truss case, laid the TouchPad over the steering wheel. The HP keyboard at the bottom of the wheel - away I went with typing - and playing with the buttons.
The only thing I have done was so simple, yet keeps the switch from turning on accidentally.
When the switch is turned on there may be a green flash from the LED - this indicates the search & find mode. So wanting to know when it was off I had painted the other side of the switch with red fingernail polish.
This in turn also gave the switch a slight build-up on one side which meant it needed a lightly harder push to enable. As such there would be no accidental enabling of the power switch. 
Note: Red was the only color I had on hand, and used red to match the bezel of my XPS 630i's trim. The buttons and trim were red, but the power light was a blinding white, so bought some red fingernail polish and painted that red. Easy fix!
