Hmm...
Lightbuckler (a disk of the same power type attached to the forearm.)
Lightlighter (for the smokers out there.)
A power whip (though only the last third would need to be tactile in that manner. Imagine, of course, that it wraps around a targets neck or leg.)
A tunneler device (place it on the ground, and it starts vaporizing its way into the lower floors of a building or basement, leaving a 1.5 foot wide hole in its wake (just wide enough for a skinny person to slip through.)
Somewhat off topic, but a blaster grenade. You roll it into the room and it fires in every direction as it spins. Not very subtle, but grenades rarely are.
I want to add throwing weapons, but that would be somewhat difficult given that light-weapons intrinsically need a power crystal to generate the blade. The only exception, I suppose, is that you could embed a smaller crystal to handle the smaller blade. The only problems after that would be expense, and weight, given the parts involved.