Minting an "I Owe You a Beer" Currency

"I owe you a beer."

A lot of people at work have saved my butt when things got too busy for one person.  I tend to say "I owe you a beer," when this happens.  How do you keep track of all those beers?  To solve that problem, I've decided to mint my own currency, pictured here.

I give 'em to people who I owe a favor to, and they can hand them back at any time and I'll redeem it for a real beer. I'm a central bank, with a private currency tied to "the beer standard."

There are still some details to sort out.  For instance, what's the exchange rate?  Certainly, a beer is about equal to a well drink ... but what about call drinks, or a roy rogers, or fancy wine?  (Is boxed wine the penny?)

It's pretty easy to get custom-made poker chips.  I used American Prom, who have an online design tool.  They shipped quickly and looked just like the on-screen mock-up.  There are jillions of other places tho.