Yup, I've got a whole colony of them going on in one of my cubes. I vacumed the sand one night, and the next morning when I turned on the lights in the tank, there were hundreds if not thousands of them cruising all over the tank. They soon settled on the glass and back into the sand. To me they look like sand fleas, but everyone told me that they are copepods, and they look just like yours.
SaltyMist, they could be the sand flea things too. I had those as well as copepods in my fuge. Or maybe i had sand gnats lol. They swarmed, and it was cool.