We got some custom boards printed up here:
http://mywhiteboards.com/custom-printed-lap-boards.html
We got the 1-sided 9 x 12 boards.
You submit your artwork as either a vector art file or a high resolution jpg. They'll have an in-house artist check it out and if things are good, they'll print them up. They take 2-3 weeks or so, which isn't bad if you submit the artwork during build season. We had to order a minimum of 6 (I believe), so we handed them out to other teams. At $6/piece, not bad.