Tiger bee fly
A hoverfly rests, hanging upside-down from a clover flower.
A small fly on a leaf, looking cock-eyed.
A peacock fly holds its wings up in a courtship display. The subject of its attentions proved to be entirely uninterested -- not surprisingly, since it was in fact dried bird droppings.
A female hoverfly (Toxomerus marginatus) pauses on the tip of a blade of grass.
A bee-like robber fly on a yellow flower, alert for prey.
A close-up photo of a syrphid fly on a purple flower.
Male green midge?
Still working on an ID but thinking Chironominae