recently a friend of mine--whose musical taste and opinions i highly respect, i should note--said that he doesn't think people should do doubles unless they have 3 tables. i disagree strongly...i think all of us techno heads need to remember that it isn't how you do something, it's what you do. whether that means 2 tables, 3 tables or 4 tables, it's going to blow either way if the dj can't take advantage of the tools he or she decides to employ.
that said, i think the prupose of 3 turntables is to give skilled djs another outlet to improve their mixing. a lot of my favorite experiences have been seeing people like jeff mills and steve rachmad on 3 tables. others have been seeing claude young or derrick may on 2. but this idea that in order to be considered great, or to employ time-honored tricks, you have to spin on 3 tables? no way.