^^^ I have no doubt that they're fungus gnats. Matt's pics look like fungus gnat larvae.
My previous post:
Sounds like fungus gnats. I'd put yellow sticky traps around your soil to get the adults, and add mosquito dunks to your water to attack the larvae. The gnats themselves won't hurt your plants, but the little larvae/maggots will eat smaller/newer roots. They really aren't that harmful, so you don't need to be too worried. Still, might as well try to knock them down as much as you can.
Search here for info on fungus gnats and you'll find a bunch of different approaches to dealing with them: layer of sand over your soil, nematodes, different sprays etc.. Personally I've had the best luck with simple sticky traps. Lots of them, like at least a couple under each plant.
And, the important thing that I forgot to mention (posted by grobofotwanky): If its fungus gnats just reduce watering. They'll go away.
