I don't know that I would actually use this but I love the concept. It's a program called BillMonk and it tracks the things you have borrowed and the things others have borrowed from you.

Borrowing is awkward because people forget, notes the site, urging me to click on a friend's name for details.

When you drill-down for details about a particular friend, you see the money transactions between the two of you, as well as the stuff that you are borrowing and have loaned out .

You owe Bob for gas and the cable bill, and he owes you for lunch. We do the math to find the balance: $30.50.

And for a spectacularly bad, very 1990's idea there is Dinner in the Sky. A big-ass dining table is hoisted into the air on a crane and then you eat. To build your team or whatever.