You see a lot of TV advertising these days for what is called a rotary tool, this is like a small drill that takes all kinds of different bits with small 1/8th inch shanks.
Very similar machines are made by Dremmel, Sears and Black & Decker. Are they really worthwhile.
Yes.
The key is the wide variety of bits, and the variable speed control that allows you to do anything from polishing to grinding to cutting with different brushes and wheels. Then you can drill and sculpture with a wide variety of miniature drills and cutting heads. Add to that the ability to fit in into a bench holder for stationary work, or add a flexible shaft for dentist like work, of drop it into a router like base or a drill press rack, and you can do a wide variety of things well although all on a small scale.
Not recommended - but useful tip.....
You can never get this kind of close up delicate control with a regular drill or router. Yes I even once rounded off the edge of the dental post in a broken filling in my own mouth when I didn't have time to get to the dentist right away. It kind of looked like I was trying to commit suicide while looking in the mirror, but my tongue sure appreciated getting rid of that sharp edge and I got compliments from my dentist for such a good job.