I would finally be able to roll a cigarette. I would make strange guitar noises while watching the guy above me fist android girls. If he would let me.
This has been a dream of mine for many a year now. I'd have it built into a claw, then overlay it with synthetic skin. Then I'd figure out a way to get the fake skin to melt off on command for when someone crossed me. Awesome.
No, I reckon I'd put a little camera on it and get it to crawl into vents or something, popping out to throttle my passers by, then have it scuttle back to me with their wallet. Maybe conceal it on my person to leap out unexpectedly at the very mention of anything remotely insulting.