I have a lot of experience with glory holes - I live in berlin (germany) and that may be a different story over here (sorry for my bad english).
I went to technical university here in berlin and one of the restrooms has a stall with a glory hole (I have no idea who put it in there; you could tell they tried to close it several times, but whoever re-opened it again and again so they gave up trying to close it after all). And I know the other universities have them too, as well as some public libraries do.
my favourite thing to do was sitting in that first stall (which is next to a long row of urinals) and peek through the little hole in the wall towards the urinals, watching the guys coming in, taking a piss, shaking off.
the wall to the next stall has a nice glory hole (smooth edges) and I used to cover it with a piece of toilet paper, just leaving a small gap open so I could look through to the next stall (didn´t want visitors to be alarmed right away). I think most of the guys knew that there was the hole in beetween those first to stalls cause most of the guys avoided using them.
but the ones who did use it wanted to get or give a good blow job ;-)
I think a lot of the ones who where interested in getting head where not gay, they just wanted to get rid of that boner they got while listening to boring lectures. I had a lot iof fun these days!
for the ones wondering about safer sex: I never let them shoot in my mouth (you just need a bit of practice to sense with your mouth when a man is about to shoot) but I did love getting it all sprayed on my chest, yummie! Anyway, I never caught any deseases.
I did enjoy sticking my cock through that hole as well, getting a good wet blowjob myself.
talking about that, I think I shoul dcheck out if the hole ist still there....will let you guys know!
anyway, glory holes can be A LOT OF FUN! just try it if you see one!