Heading into the southern hemisphere spring I'm starting to contemplate another summer of having sweat running into my eyes and down my face.
I have a couple of lightweight headbands from Netti (that I can't find anymore) that have been reasonably good. They still get saturated on a long ride though and they're old enough that they're starting to smell.
There's an interesting thread here with some discussion around this area.
I've done some research and seen a couple of options:
Aside from the incredibly lame website they look like a reasonable option, with a fairly unobtrusive design and also the features to redirect sweat away from the eyes when they get saturated.
This looks like it's very effective, but I'm not 100% sold on having all the sweat running down near my ears. Plus how would it fit with helmet and glasses?
The general opinion here appears to be that once it's wet, it's useless.