I've never done this before, but it does sound like a fun way to avoid the hassles of splitting a restaurant/bar bill when you have a big group. It's Credit Card Roulette! Here's an explanation from a Seattle Times reader:

"I have a standing weekly 'guys night' where seven to nine of us get together for beers, sometimes appetizers, or pizza, etc. ... When the bill comes, one of us gathers up a stack of credit cards. The server will say, 'Uh, split this eight ways?' to which we reply no, and one of us explains the rules of Credit Card Roulette - shuffle the cards, put them behind your back and lay them on the table one by one. The 'winner' has immunity from the bill the next week, unless that bill is quite a bit smaller than the previous bill (lowest I can remember: $23, highest over $200).

Needless to say, it keeps us all from going overboard, but keeps us all cognizant of what we're consuming. If someone is feeling their bank accounts/credit limits can't handle the bill, they are free to 'cash out' and pay their share of what they ate and drank. However, it is much more fun to 'spin' the roulette wheel!"

I actually am not sure if he explained that well. Once the credit cards are shuffled, whoever owns the last credit card that is put down on the table is the loser and pays for everyone.

This can obviously be a very expensive night out or a free one, but it's always a good way to lose the hassle of doing the math on a big bill and/or arguing over who ate/drank what and/or looking like a cheapskate/mooch.