Pet Ramps

Has anyone used or purchased any of the widely available Pet Ramps that allow your pets easy walk-in access to the back of the truck bed or SUV cargo area? My pets are getting old & are no longer able to jump in & out of the vehicles anymore and lifting them in & out of the truck is too much (they are both 100+ pounds). I saw the two that Cabela's offers which look nice but was wondering what any other pet lovers might have found. :p

Rather than pay $100+ for a commercial version, I'd try a homemade version first. Get a 10 ft length of 2x8, cut it in half and put a hinge in the middle so it will fit in the bed, and tack some carpet on the side opposite the hinge (2 pieces, 5 ft x 7 inches, you can probably get them free from a carpet installer).