As foambeetle said, permanone works well...but there are cheaper ways to get the same effect. Again, the active ingredient in Permanone is Permethrin at 0.50%.
You can buy bug-killer solutions with 10% permethrin at your local Ace.
Dilute it down to .5-1% (with water) and spray it on your clothes. When it's dry, it hardly has any scent at all (unlike deet). It's non-toxic to humans and actually KILLS bugs, where deet only keeps them off. You can fill a squirt bottle full of the stuff for less than a buck and it'll last about 2 weeks.
Just spray it one your clothes/gear/etc....it's not harmful to get it on your skin, but the chemicals/enzymes in your skin degrades permethrin and eliminated it's effectiveness.
Hi-Yield 38Plus is another product that is a whopping 38%. I was just told about this stuff. 2oz. of the stuff mixed with a gallon of water makes for a .60% solution...
Ortho makes a product "Basic Solutions Lawn and Garden Insect Killer" is inexpensive, and is also permethrin based, containing 2.5%.
Cheap, nearly scent-free,non-toxic and it'll actually KILL those darn mosquitoes (and everything else)!