I have actually jacked the bike up off the ground (motorcycle/ATV jack) and run it. The squeak is definately coming from the back wheel. I used a stethiscope and listened all around the front pulley area, and it's nice and quiet and smooth.
As a sidenote, I've been giving this alot of thought, and I've decided that at some point someone has installed the wheel and adjusted it incorrectly, leaving it crooked. This, in turn, has caused the belt to wear funny and now it's squeaking. My next step, once I get the bike back over here, is to readjust the belt so that it's squeaking again, and then spray some belt dressing on it. If it stops squeaking, it's the belt. If it doesn't, I need to keep searching.
Also, according to the local Yamaha dealer, they only want two hours labor to replace the belt. That seems awfully low to me. My Buell (earlier tube frame type) called for 5 hours labor, and it was a much simpler bike. Is there something I'm missing here? Is it that easy to remove the swingarm from a Road Star?
Thanks again for your help.
I'll let you know what I find.