laptop cooling

Can anyone recommend a laptop cooler that works when you have it on your lap?

I can see a couple on scna, but am unsure if they are suitable for use on the lap

http://www.scan.co.uk/Products/Produ...oductID=420908
http://www.scan.co.uk/Products/Produ...oductID=274613

There's also this one: http://www.scan.co.uk/Products/Produ...oductID=381922