Thanks for the tip, Mark!
Last year, I was cutting old canes when I watched a queen stroll out of a trunk cavity. As she sunned herself, grooming, probably fully enjoying the spring day, I whacked her head off with my machete. My poor buddhist boyfriend gave me a withering look, but just today, he hunted out the queen of the colony that had been the bane of our summer existence, and did her in with glee.
Curt, buddhism be darned, found that he prefers the bag traps to the plastic cylindrical traps. We caught WAY more with the bags, though they're about five bucks each. You don't have to clean them as much, and the attractant doesn't dry out over time. Plus, our yellow jackets are monsters, and I think they can get into the bag traps easier.
They often go on sale this time of year, so keep an eye out for them and grab 'em while they're cheap.
I'm also going to try and make some of my own traps, since the cost does add up.