Pretty respectable closeup from a non-macro lens, huh? It's a Wheel Bug: http://bugguide.net/node/view/454 Arilus cristatus. Watch out - it has a painful sting when harassed.
Isn't it incredible? That dinosaur crest on its back just blew me away. Totally fascinating. I've put a couple of pictures on bugguide.net to have it identified.
This has been an incredibly dull summer insect, flower, and wildlife-wise. I go out several times a time to see what photo ops have arrived. In the case of this image I was actually out there to collect impatiens seeds and spied this guy who is about 1 3/4" long. Pretty imposing size. I sure wouldn't want to find one on my kitchen counter!