Moving house soon, so various things need to go including an adjustable kiteboard rocker table/jig.
Not really sure if this would be everyone's cup of tea, but if you can't be bothered with vacuum pumps and resin, or can't get those bricks to keep all your ply in contact, this thing seems to work.
I made it about 2 years ago and have made a few boards with it (one glass/epoxy, and a couple of ply boards) - all have turned out pretty well and are still in one piece (although probably more from lack of use. humph.. )
It's not quite as clean and shiny as in these photos, as it's had a fair bit of resin spilt on it, but stilll works. Seven independant adjustable mono-axial compression nodes allow you to set a range of asymetric rocker contours (oh ok.. the wingnuts and wooden slats mean you can set the shape! ) and hold it in place until your resin/glue has set... you can crank it down pretty tight too.. and shove in some form of mould to get the base concave if you're working with foam..
http://chinook.hope.mediaisotope.com/temp/108_0868.JPG
http://chinook.hope.mediaisotope.com/temp/108_0871.JPG
It's in Bath, and I can deliver it to bristol or even croyde/wooly (or between) if anyone does want it.. otherwise it's bonfire time..