@Triode: I do indeed wear a helmet, and when the weather gets colder I wear a thin skullcap that I bought from a sporting goods store. On particularly cold days I wear my
Ninjaclava.
I appreciate all the responses thus far... please keep 'em coming! I am curious about the GUTR and Halo in particular since they both are designed to direct sweat away from the forehead to stop it from dripping into the eyes. I am a profuse head sweater and I find that riding in the summertime often leads to eyes that are burning from sweat, and rivulets of perspiration running down the lenses of my sunglasses. I've tried soaking my skullcap in cold water before riding, and it works initially, but it eventually becomes saturated and I end up with the same problem.
The terrycloth patches on the thumbs of my gloves are woefully inadequate, and they end up pretty funky after a few rides.