I've been a beekeeper for over 10 years. I'll let you in on my little secret on how to get rid of wasps, yellowjackets, carpenter bees and honey bees. It's not expensive AND it's on the shelf at your local grocery store!
The secret here is that bugs like the above mentioned do not have noses like you and I. These little buggers breathe along the sides of their thorax or abdomen. There's a line of holes down each side. So the easiest way to get rid of these wee beasties is to DROWN them. And the easiest way to do that is with liquid
dishwashing soap. Now you can do like my wife does and buy the good stuff (Dawn) or you can buy the cheap stuff (generic), it really doesn't matter. Take your 1 gallon garden sprayer (we all have one of those) and pour 1 cup of liquid
soap into it and fill with water. Then proceed to spray the cr*p out of the nest or offending individual.
The solution lowers the surface tension of the water and the water flows much much easier and drowns the wee beasties. It also really screws with their ability to dive bomb you. BUT
a word of caution...once you start this process you will certainly in no uncertain terms "stir up a hornets nest". So if you have a small nest I would say attack with fervor during the daylight. If the nest is 3-4 stories high (or a common yellowjacket nest like we have here in Oklahoma), wait until night time and douse the thing until it's completely soaked. They won't dry off and fly away, they will die almost instantly. And since your doing it at night they won't be able to see very clearly. Also the soap contains no harsh chemicals that will poison the area.
And then there's this way: http://www.wikihow.com/Kill-Ants
I learned this from an older beekeeper who used it when he would remove honey bees from a house. He'd always leave a honey trap behind for the ones that weren't there when he cleaned the hive out and come back the next day and spray them down.