I've been getting a lot of calls & e-mails lately about fruit flies and how to get rid of them.
All you need is about a half-cup of cider vinegar and a couple of drops of dish soap. Put the vinegar in a small jar, add the soap and set it on the counter.
The flies are attracted to the scent of the vinegar, fall in and because the soap coats their wings they can't get out so they die.
Personally, I use just a little bit of left over sweet pickle juice and some dish soap with the same results.