How did I not know about these sites before?! Here are Nature Closeups, a lovely, lovely website full of macro pictures of insects, and BugGuide, an identification website developed by the same person. Not for those who dislike creepy-crawlies.
And here is a considerably less pretty picture I took this weekend. It’s been tentatively identified as a caddisfly (order Trichoptera). The larvae of these insects are aquatic and, in many species, enclose themselves in cases they build out of silk and whatever debris they can find.