Improvements

I've been using my own two self-made ones, and I reckon they're even better: they tilt the base of the laptop to 45degrees, hence the alledged cooling effect should be much stronger as there's a better flow of air.

Also one of them consists more or less of two triangles with a hinge, making it easily transportable.

And both are wood painted with hammerite, THE choice for vanguard fashionistas --- coloured half-transparant plastic is out, white plastic is past, shiny black is passe...