A few years ago the garbage disposal was leaking a bit and needed to be removed and the drain resealed. Easy chore I thought -- well there is a compression ring around the disposal that is held on with a screw. I try to get my stubby screwdriver up in there to unscrew it and "bam!!!" it snaps off. So after a good half hour of cursing, I remembered that I had purchased a close quarter drill a few years ago for just such tight spaces. I chucked up a small Uni-Bit and proceeded to drill out the entire screw and bracket in just a few minutes.
Saved my aching butt!!! This tools is worth the $30 you pay when they're on sale -- I like it a whole lot!!