You can take the end piece apart and use thiswhat would one have to do to replace the existing clicky switch in the back with a momentary switch? much like how davidinwellington has it but at the other end. This way it would be much like another "tool" that so many vaporheads seem to like.
3A 125V SPST Pushbutton Momentary Switch - RadioShack.com
or the sub minis momentary would work too have to make a spacer of sorts.
easiest way is to just do it -