This is primarily a two diabolo site, but here's a bit about three anyway! I can't do three diabolos. But Guy Heathcote can. Every now and then, people ask for videos of Guy doing three. I filmed the following two videos at the Bristol Juggling Convention 2002. My camera's batteries promptly died as soon as I started recording, so what you see is all that I managed to get! Thanks to Guy.
And for comedy value, here's a video of my best attempt at the same trick
Update: 3rd Nov 2005 - Actually, I'm doing a lot better with 3 these days. I'll put some videos of it up at some point, but this site will stay focussed on two diabolos. There's a lot of stuff about 3 on the diabolo.ca forum.