I saw such an instrument in Micro Anvika and it worked by rubbing away a thin layer of the bottom of the CD (either a proper or burnt CD). Sorry, I can't remember what the bufferer was called since I didn't buy it, nor have I seen it in action. If, however, it did work I certainly have a few CDs in need of buffering (so to speak).
I've seen something called "Disc Doctor", but i can't remember where. You put the CD into it then crank a handle, it spins and re-surfaces the disc. Might have been in a branch of Electronics Boutique come to think of it. (which is now "Game" i believe)
If you have a CD writer, try this.
Rub a tiny amount of any light oil, olive oil does the job, onto the srface of the disc using a very clean cloth or tissue. Then make a copy of the disk. Some scratches are beyond any treatment if the data is corrupt.
You can get this thing in Virgin for around 30 squid that will clean the surface. Suppose to repair light - medium scratches. Works pretty well. Borrowed a mates. Toruble is that no matter how fast you turn the handle it 'drags' the CD at the same speed through the cleaner.