I never have, but I would if I was truly interested in the scent they were wearing.
Where I live, most males wear after shave, or, at best, something like Le Male
or Acqua di Gio--not that there's anything wrong with that.
I've never smelled a male in my area wearing anything like Egoiste, or Tiffany for Men,
much less a "niche" scent. Nothing I've been interested in knowing about at any rate...
I will say this though, I think in the future I will be more forthcoming with females
who I think smell "good." I don't have nearly as well rounded a knowledge of women's
fragrances as I should, and that could be easily remedied by simply asking what a fine smelling
woman/girl is wearing.