UPDATE: 03/09/2009
One of the rear brake calipers was sticking and heating up the wheel (I could smell brake pad), so I took it into the shop.
When I got it back I discovered that the truck does indeed roll.
They noticed uneven wear on the caliper the previous owner did, and realigned that too.
I'm guessing that I'll get another 2 mpg, because it felt like the truck was in 4wd when in 2wd before.
I'm considering a new paint scheme after I fix the rust. I'm still playing with the roof and hood transition stripes.