I have used this before with success, wanted to see what you guys thought. Now, this only works if you have a built some rapport with the bartender/waitress/shot girl that you are using it on, this likely won't work as a first line.

You: So, you must get hit on all the time, huh?
Her: She'll say yes, most likely.
You: Ya, it's amazing that some guys can't just let a girl do her job.
Her: Ya, its annoying sometimes.
You: can continue the conversation...

But, after building this up you then say... "So, when can I take you out." You say this in such a way that she can't really tell if your actually asking you out. But, if you have done the ground work, you have successfully disarmed her from all the guys that bother her and she will likely take the bait.