I just got the tri-fold tonneau cover from Tonneau Pro. Install was a breeze and looks great. Too soon to tell if I am getting any better gas mileage but I didn't really get it for that. I wanted some styling and security. Anyways here are the pics of the cover on my 2008.
Dont mind the pollen. It is out of control here in NC right now.
Good luck on your hunt for a cover.