I use mine all the time, it's really unbelievable how well it works. I clip mine to my belt while practicing in the yard or shooting a 3-d course, as long as you aren't running it will keep up and keep the bugs at bay. Also when you buy refills buy the 4 pack for $18-$20 it'll save you a few bucks in the long run.

Has anyone used the earth sent packs yet? http://www.mosquitorepellent.com/Ear...-Fall-Pack.asp

Also it says to lay it flat and not horizontal does anyone just strap it to the tree anyway..... and does it still work as good that way?

I've used them and they don't smell anything like earth scent. They work just as well to repel the skeeters though.