This is a Dolichopodidae, also known as a Long-legged Fly.  There are over 137 species of them in Florida and  18 of those have only been found here.  They are very small.  Less than a 1/4 inch and even less than 1 millimeter.  You will see them flitting about everywhere.

They are carnivorous and eat even smaller flies (think no-see-ums).  They will often return to a preferred, predictable observation spot when feeding.  When they take off, they leap backwards and I noticed they did so every time I clicked the shutter.  I expect it was reacting to the movement of the lens and iris.

For this picture, I set the focus point on the edge of the leaf to the right and waited for a fly to return to the leaf.  I set the camera for a fast series and started shooting.  Eventually, I found a couple worth keeping.