I saw them in the mosquito repellant section at Wal-Mart last season. Thought about buying one, but they are rather pricey.
I do think I'm going to bite the bullet and get one this year though. When we go up north camping we do use quite a bit of mosquito spray. We mostly spray it just on our shirt/pants, but if we're in shorts we do use it on our bare legs, and we spray our neck and ears and I'm starting to be concerned about too much of that stuff getting into our bodies, so I'm thinking those new repellants that just attach to your clothes might be a better idea even if they are more expensive. And I know you can get refills for them. If they work it would sure save on all that nasty, greasy feeling spray on our skin.