This review says it's a gimmick with no value (after testing):

"The LapCool3 is a good idea, but ends up being a gimmick. There is absolutely no reason for you to spend money on this notebook cooling solution, and I would advise you to drink four beers instead and slip the bottle caps underneath your notebook's feet. There are some folks who will be taken in by the promise of notebook cooling and the convenience of USB power, but I hope you aren't one of them. This is a good idea that should have died after the first test. Because of the poor performance I award the LapCool3 3 out of 10 hats and the PimpRig PimpSlap Award."