This page describes an alternate method of recycling classic game catridges for new ROMs - whether Betas or your own software. I find desoldering the old chip(s) and cleaning the pin holes to be very time consuming - this method brings the board preparation down to about 5 minutes with the help of a Dremel or other cutting tool. There is also less chance of lifting traces due to heat (although there's a chance of cutting them! Be careful!)
If nobody else has already grabbed this technique, I would like to follow other hack pioneers like Tom Duff and name it the Tursi Technique (TT for short). ;)
If you're going to try this, DEFINATELY wear eye protection and you should also wear a dust mask! There will be bits of metal and plastic, circuit board, IC shell, and other dusts floating around that are not good to inhale!