I recently completed assembly and road testing of my semi-home-made bike rack that sits over the tonneau cover on my truck. It and the bikes survived the trip to Chincoteague, VA and back last weekend (around 4 hours each way).  I wanted something that sat up just high enough that I could roll up my tonneau cover, but didn't require drilling.  That meant using the stake pockets.  The only manufactured one I could find that's similar to it is the ProRac Tonneau Rack. I didn't care for their implementation, and it's expensive at just under $500.

Here's the Thule rack:

The Thule rack is the exact same rack that I had sitting on in the tracks  on top of our pop-up -- 430 Tracker II Foot Pack (includes 4 feet), TK1 Tracker Kit (4 mounts). two 96" Load Bars cut to about 88"-90", and three 599XTR Big Mouth racks.  The buyers of our pop-up didn't want it.

And here's the rails I made to attach it to the truck:

I used poplar, and everything's glued and screwed together using weatherproof glue and stainless screws.  A 3/8" lag screw secures the uprights into the stake pockets.  It needs some sanding and a finish coat.  I'm debating on using polyurethane or if I should paint it, and if paint, green to match the truck or black to match the bed, tonneau cover and rack.

The rack's feet, which you can't really see because they're in the grass, lock onto the mounts attached on top of the rails.  I think I could fit six bikes across by alternating them front-facing and back-facing, assuming I had more Big Mouth racks.

Once I get it finished, I'll post some better pictures of everything together, with bikes on it.