Who cares what kind of insect this is, I am just so proud I could, for once, accurately and firmly state how long it is. It helps that it was on the screen of my back porch and I could go back later and measure. Anyhow, nose to tail, 12.5mm. I didn't count the antenna, but I could, because it was on the screen. This could be my proudest moment here at Bugguide! ;-)

More seriously, this was a pretty convincing mimic of a square headed wasp, which is what I thought it was until I viewed the photos on the computer. The pretty eyes remind me of a horse/deer fly.