The ones with the privacy snap work very well on bikes and ladders, etc. XDH wore them pretty much exclusively, even when he commuted daily.
I'd use that snap a lot- running, biking, etc- if I had one. As it is, the kilt comes out for special occasions. I've got the black standard kilt with the silver rivets and wear it with a thick leather belt/silver grommets. ...with my work boots. It's a certain look, but very, very nice at summer festivals etc where it's really hot.

looks very good on guys w/o shirts and if you go to the OCF in the summer, looks pretty good on girls w/o shirts.

(hey, we're on a thread talking about going commando. I figure it shouldn't be that much more taboo to talk about going topless where legal and acceptable...)