You can check out his front page to see when he'll be streaming next (and someone told us he was streaming for something like fourteen hours the other day -- take care of yourself, Tim!), and if you're interested in how you might get started multiboxing, he and his chat channel are probably more than happy to help you figure out how to do it. He did say he'd be streaming every night this weekend, so if you're around then, you should be able to catch him. Personally (as you probably already know), I'm a big fan of the standard one character gameplay -- I have enough trouble figuring out one toon, much less five. But Turpster, as you've probably heard on our podcast, has dived into this kind of stuff headfirst and loves it, so if you're interested in seeing how it works, tune in to Tim's channel and find out.
Update: Apparently while this was presented to us (and appears to be) just a guy streaming his multiboxing, Tim may have some less generous motives -- he's apparently trying to sell multiboxing software, and you can see the comments below for some other shady moves that have been made. Watch at your own risk, and keep in mind that while the stream appeared legit to us, it may be an advertisement for software you certainly don't need to multibox.