Good Idea, Bad Idea, the Pickup line Edition.
Good idea - Draw a stick figure picture of her on a piece of nice paper and sign it while she's with her friends, walk over, apologies for interrupting, and say "Pardon me, Miss, But you have inspired me to high art. Apologies again for the interruption" then give your best boyish grin, and walk off. When you hear the laughter, turn around, and either raise your glass at them, or take a little bow.
Bad Idea - GET IN THE BACK OF THE VAN!