Hah! Just as it was I saw a program on TV the other night about large scale glass production and they quickly went over the machines they used to cut the glass and there was basicly two options 1: FlowJet (Water and Garnet flakes) or 2: A CNC machine with a diamond tipped scoring tool on the business end. The FlowJet seams kinda unrealisitc for a small shop (but it would be fun) and the 2nd option could be ghetto rigged from a glass scoring tool which isn't hard to come by.