I usaly go caching with the baby or friends, so we just stop and talk. No one wonders why i stop anywhere to talk to the baby, mothers do that.
If i'm on my own i usally just say "have you seen a (pet) ferret?" i don't like to lie to people, i think i have plenty of tells, so i prefer that one. And also that allows me to look around a bit without looking suspicious. And when i "give up" it is not so strange eigther.
But i DO get some strange looks when i go out buying little zip-lock bags for putting in containers. I think the asume i'm into drugs. Someone even told my friend that they didn't sell "drug bags"...