There's also the LNH logo I've always used:
http://www.physics.ohio-state.edu/~dvandom/LNH/LNH1.GIF
I'm sure that could be turned into something better by just about
anyone. It's based on the LSH logo with the L* in a circle.
Dave Van Domelen, also officially releasing the design for use in any
LNH-related webpages, etc.