Unless I'm in sweats, I always have one with me, usually in my right back pants pocket. I use them mainly for cleaning my reading glasses and occasionaly for mopping my brow. It goes in the laundry hamper every Monday, usually without ever having been unfolded during the previous week. Over the years I've built up quite a back stock from getting them as gifts.
I've given away at least four or five to damsels in varying needs of distress, some I've known and some I haven't - once to a fellow juror with a snuffly nose, another to a menopausal colleague who burst into tears during a touchy-feely leadership training class that we were required to attend, another to a date at a chick flick, etc. I always let them get them, saying I've got dozens more.