Wow, some nice stuff in this thread! I did a road trip in 1998 in my big Dodge with a cap, just threw a mattress (and a dog bed) in the back, a box for clothes, and bought a couple 2-gal water jugs (the kind with a spigot) at the grocery store which I refilled along the way until one wore right out and soaked my bed. Had a cooler in the back seat of the cab, and a bag of dog food. Spent two months in that set-up driving to Alaska, with nary a hot meal.
My second expedition I had a 2001 F250 superduty with a cap. This time i put a little more thought into it and built a small platform for the mattress out of 2x6's. It never occurred to me to have drawers, or to cut the slab of plywood to make it easier to lift. I just bought some heavy-duty lift arms (so strong I had to get a slide bolt to keep the bed in the down position!) to lift the entire platform up to get at stuff underneath. I also got a camp stove and an actual 5-gal water jug for that trip. Spent several months living in that road-tripping around the states in 2004, then tent camped for a month in the Black Hills in SD. Haven't had a truck in quite some time now due to going into business for myself which requires a vehicle with good gas mileage, and have been dreaming of getting another truck and going traveling again. I loved it and I miss it and all these build threads make me want out there sooo badly! Thanks everyone for all the great ideas. My next truck is going to be truly liveable.