They were using a miter saw with a five or six foot fence attachment and they had a computer attached to it where they would input the length of the cut. It would then adjust itself to the proper size for cutting, no tape measure necessary. Anyone have one of these? Are they cost effective for the DIYer? Also, do they fit on any saw or do you have to buy the saw with it? This one looked like a Dewalt. I'm interested but something tells me they're probably pretty expensive.