Or at least, it tries to. Since I personally haven't tried out the Mosquito Shield, I wouldn't dare put out a personal recommendation. If you have already tried it, why not vouch for its (in)effectiveness by leaving a comment? For the rest of us, here's the skinny. The Mosquito Shield is a spell that requires you to chant a 20-syllable mantra before casting. Nah, I'm just kidding. This is actually a portable device that comes with cartridges of Geriniol which is said to be a "natural, chemical-free odor that has been field-tested to repel mosquitoes."
All you need to do is clip it to your belt and those pesky bloodsuckers will avoid you like the plague. No idea if Geriniol will leave an undesirable smell around you though. At $20 a pop, the Mosquito Shield is certainly worth a try if you're planning to go on a camping trip this summer.