Well, using a 'line' (and I hesitate to even word it like that, it sounds so cheesy) is totally dependent on personality, and seems to me, I just don't see you (s4ndm4n) feeling comfortable with a line. If you were, this whole thread would be a non-starter.

Just saying 'hi' is appropriate for the contact you've both been having--quick little glances and of course that lonnnng one earlier--and it's non-threatening. Can be done quickly, and never underestimate the amount of emotion one can put into a simple greeting like 'hi'...especially if if includes a friendly "I recognize you; we don't know each other but we're certainly not strangers" smile.

Then, of course it could move on to badinage, but...at the speed you feel comfortable. C'mon...it's only a word and a smile. I KNOW you can do that!!!