McNally's rig #1-
http://www.joemcnally.com/blog/2008/01/28/...lly-tripod-rig/
Manfrotto also makes a projector stand that screws into any tripod head. No room for a mouse, but I like that it's textured so the laptop won't slip around if bumped.
Since I only do tethered in the studio, I have a small table that I use, but it's decidedly inconvenient to move around much. I'm considering getting a small rolling cart from anthro that I can also use as a power station.
This looks promising for something pretty mobile (if spendy): http://www.anthro.com/computer-furniture.a...justable-height
A bit bulkier, but for studio use I find I really like small wheeled kitchen carts sold at home improvement and hardware type stores as a place to keep my laptop, 24 inch monitor, mac pro tower and all the bits and bobbles I like to keep super handy in the studio (pens, model releases, grey card, gaffer tape, 4 medium clamps, pocket wizards, scissors, 2-sided tape, spare hard drive etc etc). I secured a power bar on the back, and keep a 50 foot extension cord with the card, so I can roll it anywhere in the studio. Shooting with a 12 foot USB cable, I can roll the card 'near' where I'll be shooting, still have some good range, and if I need more, the card moves in 5 seconds. I can also very easily adjust the angle of the cart so clients or models can see (or can't, if I so choose).
Since I keep gaffer tape at the desk (usually hung on the handle of one of the clamps clamped to the side of the top surface), I will put a small bit of tape on the computer to hold the USB in place, another smidge of tape on the bottom of the camera. The laptop can be clamped down if needed with the clamps, a bit of tape, or just sitting on the no-slip rubberized stuff I keep under it.
I've seen a lot of more elegant solutions, but none so useful for under $100.