Cooling a laptop

[Heifetz]

I use a macbook on my lap very frequently, and it gets pretty hot. I'm thinking it's probably not a good idea to be exposed to it for a long period of time, although I try to keep it on my thigh more than my groin area. What do people use as a buffer between the laptop and themselves? I searched a bit and came up with the thermaltake cooling pad. Anyone here use it?