This, as INQUIRER readers well know is a particularly dodgy practice. Aside from heating genitalia in an alarming fashion, worse could befall the over-heated user. A reminder of the worst that can happen, should you need one, can be found here.
Coolermaster's Notepal is a USB-powered grid, designed to keep the base of your laptop cool. Its wee fan circulates air around the underside of your laptop channeling away all that heat.

The grid itself is a pretty classy design. And that fact that it draws its power through the USB connection means it's as portable as your laptop itself, with a reasonably insignificant power overhead.
Pricing for the device isn't yet available, but considering the possible alternative, it'll be cheap at half the price. µ