I thought I was smart to snag a half dozen woolrich caps for $4 each, a deep magenta color wool. I packed one away in each of our emergency supplies, they're good in rain too. They were terrific, until #1 son progressively lost 5 of them on various hikes. I swear the kid has a black hole in his pack somewhere.

Countycomm has/had a very nice fleece version on their site, it works for cold outdoors and doesn't grip too much. I'll have to keep my eye open for the smart wool version.