For the month of December, I'd like to offer a promotion of sorts where I donate a certain amount (say, 25% of the order) to a charity of the customer's choice. To do this I'm envisioning a form checkbox or drop-down menu to select from a list of 10-15 charities, and a database field to store this choice and the order amount $$$.

Does this idea interest anyone? My PHP and SQL expertise isn't advanced enough to start from scratch. I'd be willing to help however possible though.