I've been known to wear a vest on occassion but not every day. I tend to do it when I know I'll be travelling between offices and working up a bit of a sweat... strangely, it seems keep the BO to a minimum.
That is definitely not the case for all vest wearers though!
To keep the sweat from showing through a shirt. I don't get it personally as it would surely just make you sweat more but hey, they wear flares too so who knows the method to their madness?!
