i think it's an unsaid rule to not hit on a waitress.
they're doing their job being nice to you, and it's hard not to think that they would get hit on all the time.
so why just look and be like everyone else? be nice and be respectful - and then if you see her outside of work one day and you two talk a bit - _then_ test the waters and see if her interests are possibly in you instead of your table and tip.