Ooh, this is great. Thanks for the responses!

I really like the idea of a trackball for the second character. Might also make it a little less confusing when grabbing for the mice in a hurry.

I've thought about the X-keys pro as well, but I'm still not sure if I should go USB or PS/2, since there's still a good chance that I may end up hardware 5-boxing somewhere down the line.

Things are up in the air until I can try out a Death Knight/Priest combo, and see what the 70-80 shaman changes are like.

And the funny thing is, I already play my paladin and priest in a way that most people think I'm two totally different people.

Are there any more stories/experiences about 2-boxing?