I liked the idea so much I developed it into a universal grip switch, and then added an ignitor too. Basically it's a 45 style aluminum pistol grip with a trigger (trigger not shown), a switch that is actuated by the trigger, wood grips, an ignitor, some brackets and hunk of aluminum extrusion you can mount to anything with a 1/4" hole to.
Everything together is pretty expensive $110+ but if you strip it down to it's basics: the frame, the trigger, the switch plate and the switch, it ends up being under $45 (second two pics).
I'm hours away from putting one together; the rest of the parts are on a UPS truck.
EDIT:
Google's Picasa web album is having issues, the pics aren't showing...

here they are uploaded: