This tray, which I think I got at Target, cost somewhere between $10-15 bucks. When I couldn't find anything suitable in the computer department, I found this serving tray in housewares. I figured it would fill the bill...with a minor alteration. Brought it home and had Hubby cut the front side of the tray off. (The front section came up too high and blocked access to the keyboard unless I arched my wrists.)
Not a very classy solution, it gets put up at the end of the day, out of sight. Cheap as this sucker is, the side braces have worked their way out and had to be re-glued. And the finish is gummed up on the side pictured here...other side's finish is smoother. Still, works for me! Keeps the heat of the laptop off of my legs and provides a steady surface to boot.
So, AM I the only one using a serving tray for a lap desk?