If you've got a pickup, you've got the ultimate portable camp. Compared with a tent, it provides a less conspicuous (and more secure) shelter at the put-in, by the trailhead, and near the breakor at the rest area. Some new trucks, like the 2007 Toyota Tacoma, have notches in their sidewalls to hang a bed, but this design will work with any model.
Cut two 2x6's to the length of the bed, usually six or eight feet. Drill four evenly spaced, 1.5-inch holes halfway through each beam. These holes will accept the one-inch-square stainless-steel tubing. (See Shopping List at right.)
With a hacksaw, cut four lengths of one-inch-square tubing to the exact width of the truck bed minus one inch. Be precise: The steel pressing the beams against the bed walls is what holds the whole thing together and makes it easy to take apart.
Use mending plates (doityourself.com/icat/mendingplates) to connect the 2x4 legs to the 2x6 beams. The bed height needs to clear the wheel wells, with enough height to store gear bins.
Finish it with a deck of plywood (usually requires two sheets). Screw the plywood down or leave it loose for easy disassembly.
Skip the cheap foam mattress. To save space and avoid mold and odor, use a thin Pickup Paco ($267; jpwinc.com), a heavy-duty, pickup-bed-size sleeping pad from Jack's Plastic Welding.