How do I get rid of gnats?

I just asked about getting rid of ants and after trying several tricks I was able to get rid of most of them. I still find one every now and again. One of the helpful tips was to buy a mint plant, so I did. And along with it came the gnats. They are now taking over my house. I have put the mint plant outside but the gnats did not go with it. Does anyone know any tricks to get rid of the gnats without attracting anymore bugs?