I’ve never been that bothered about laptop coolers. These tray type things sit underneath the laptop and have fans that help your portable computer nice and cool. However, I picked up a Microsoft one recently and it actually turns out to be quite useful. Not so much for the fan, which I don’t really think a properly designed computer should need, but for the way it keeps the machine off your lap. The Microsoft one also has a foot that you can use to bring a portable to a better angle to use on a desk.
All things considered there are worse ways to spend 13 pounds or so.