I just thought I'd share this with you guys, my buddy and I just finished a couple of homemade indo-board-type-balance-trainers.
All we did was get a piece of ply, cut it to the size and shape we wanted, cut and nailed bumpers to the ends so you don't roll out and land on your head, picked up pieces of 4" and 5" diameter pvc (whichever you prefer), wrapped duct tape around the pvc, and coated the top of the ply with that non-skid additive stuff for paint. And ta-da! Indo board.
It works perfect, duct tape is just enough traction but still allows you to ATTEMPT ollies and spins. Fun to play around on, especially on a rainy day when the lake is a no-go or when you're around drunk people : ) I think it works great as a surf trainer.