Were you ever in a situation where you wanted to impress a sweet waitress in a pub, but every time she approached, you forgot your lines and your tongue got all dry? Here is the perfect solution.:
When she comes over with the bill, present your credit card and point out to her the card details: the number at the bottom, the date, the different logos etc...etc.. Now turn the card face down and give it a good shake, explain that you are mixing it.
When you turn the card back up, she'll be shocked to find out that you accidentally over-mixed; to her surprise the contents of the card will be in total disarray!
After she gets over the initial shock, just ask her for her phone number! You won't be disappointed.
Otherwise, if you get your kicks from watching your banker bounce out of his seat, I'm sure you'll have a ball with this gimmick.