I have a milk crate (the ones that hold 4, 1 gallon jugs) zap strapped to my rear rack. Where I live, it's actually a fairly common choice. It's good for a few groceries, a load of library books, a 24 case of Pepsi, even my lunch box. I used to use panniers, but found the crate to better meet my needs. Will look into modding it to hold a few more rear lights.