I won't bring up Pepsi Refresh because that has been beaten to death. But I once blogged about General Mills and Yoplait with their Pink Lid for Breast Cancer program which while it racked up money for the cause, they didn't do it in a way that in my opinion was sincerely genuine and wasted resources.
But in a recent Sunday Circular Coupons Insert I found a few that I liked. They just required you to use the coupon and buy something. No sending back lids which kills trees, burns fossil fuels, or requires dollars to pay humans to manage the program that could be best spent on the charity. It helps boost sales, and gives to charity as a reward for buying.