Hmm, very rarely these days, although maybe 10 years ago i probably wore it much more than i do nowadays.
In fact, i don't think many of my friends wear their jackets outside of biking, good thread because it's not something i've thought about until now.
I'm 55, so to be honest, i feel a bit odd if i do wear it when i'm at the supermarket, in the car and not on the bike.
This is possibly because i see quite a few people wearing biker-style jackets, when it's obvious that they don't ride a bike, it's more of a fashion statement and i don't want people thinking i'm wearing one just because they are "in fashion" at the moment.
G : )