Longlegged fly. They come in metallic green, copper, brass. They are predators and considered beneficial! Aren't they gorgeous?

"They come in metallic green, copper, brass"
or all of them depending on how the light shines on them :)
predators of what?
lol... for some reason when I was little I thought these were tse tse flies.

That would be a good name for them! If they were bigger, they would look like jewels! The adults hunt for anything smaller than they are: mites, aphids, lacewings, etc. Apparently, the larvae of these little things are also beneficial.

Here is a link that might be useful: Longlegged Fly

ah! great! I've been seeing a lot of them... maybe that's why aphids aren't giving me so much trouble :D I still see a couple once in a while, and since they breed so fast I assume I'd be crawiling with them if something wasn't eating them.