Wow, this site is great. Two pages of responses in 1 day. GREAT PHOTOS!
I have a full size (8' bed) Ram with a Cummins Diesel. I have loaded a ton of wood pellets in the truck on several occasions (2 ton once

) and it doesn't really effect fuel economy too badly (wind on the other hand...).
I was more curious than actually considering it. Loading a Smart and hooking to my travel trailer would definitely put me over weight (adding the tongue weight).
The closest Smart dealer is in Buffalo (2 hours on the Thruway). I suspect I'd get a flat bed trailer. They are handy for hauling other things as well (tractors, pellets, snowblower...).