I'm going to be honest: I really want to believe in this one. An odorless little gadget that keeps mosquitos at bay (using allethrin, "a synthetic copy of a natural repellent found in chrysanthemum plants," which is then heated by a tiny, refillable cartridge of butane) sounds like my dream come true.
And, to be fair, this thing had a lot of true believers on Amazon! For example:
"I am in Central Florida surround by lakes, ponds, and rivers. Mosquitos are everywhere in the hot, humid summer. I followed the easy instructions and within the time it is supposed to be working, the area around the device started becoming free of mosquitos. I moved the device to another section in my backyard obtaining similar results. The effective time of the mosquito-free zone was closed to four hours with no wind. Under a little breeze it lasts about three hours. Great device to have when camping or hiking." —Amazon Customer
I wasn't able to find much evidence from the scientific community about Thermacells, but the company has a satisfaction guarantee, so I'm probably going to go ahead and buy one. I'll report back.
Get it from Amazon for $21.99+.