Good show! After a bit of doubting and poking, I believe it is specifically a larva of a predatory fungus gnat in the family Keroplatidae. Apparently they use that sticky stuff in the photo to catch little critters who come along to eat the fungus! They seem to be more well studied in Australia than in the States.

http://hbs.bishopmuseum.org/aocat/kero.html

The clincher was a nearly identical photo, down to the type of fungus(!), on bugguide:
http://bugguide.net/node/view/14942