Invasion of the Fruit Flies!

Ok, this is a plea for help. My apartment has been inundated with these small flying things that I can only assume are fruit flies (although they do seem kind of large compared to the fruit flies I remember). They appeared, I think, after me or my roommate left out some bananas until they got brown. Then one time, he left out a pan of enchiladas overnight and the crap really hit the fan. The next day there were swarms of them, and since that fateful hour (about two weeks ago I think) we've had these little bugs all over our kitchen.

We now put away all food as soon as we're done eating it, wrap everything in the cupboards, clean up all messes, leave no dirty dishes out, ever, and we even moved the garbage outside onto the deck. That sort of worked, they decreased slightly in numbers. Now we've taken a more pro-active stance, spraying them out of the air with cleaning agents (which we're pretty sure also kills 'em) and vaccuming them up until no more can be found.

But, every time we leave the kitchen for more than a couple hours, there's a renewed swarm. It's mind-boggling. It's like they spring out of nowhere as if by some magical means. We have literally tried every defensive measure possible, and some offensive measures. The only thing left that I can think of is that our apartment, besides the flies, is completely free of other bugs. Maybe if we had some spiders or something, or maybe ants that would find the little ****ers' eggs, that would take care of the problem.

For the most part though, my roommate and I are at our wits' end. Has anybody else had this problem? Does anybody know what to do?

Fly paper might not be a bad idea. The vinegar trap sounds like bee traps we used to make at my dad's house (sugar water or beer in a plastic liter bottle with a downward-pointing funnel entrance). I forgot to mention, we've also tried leaving all the windows open overnight to kill them with cold but it didn't seem to do anything.

While they've definitely gotten less numerous, what I am so incredulous about is how hard it is to get rid of them. We've searched every crevice of the kitchen for left-out food and been killing them for a couple days now... where could they be spawning? I remember at my dad's house we used to have a 'compost bucket' that we'd put food trash into and then take it out to our compost pile once every couple of days, and NEVER had a fruit fly problem. I honestly think it was because of all the spiders and ants in that house.