I have a thing I got from Nashbar that's basically a stretchy fabric tube. I can wear it just around my neck, I can pull it up over my mouth, I can pull the back up and over my head so my face is sticking out but it covers my hears and front of my neck (this is the way I usually wear it).

I don't know if they still sell it, I can't find it on their site.

Searching around, the closest matches I can find are for neck gaiters. Here's one:
http://www.idahomountaintouring.com/...aiter-1482.htm

the nashbar one was really cheap, < $10 IIRC, and a little more versatile (but probably a bit less warm) than that one. I've been wearing it for 5 years now.