One of the races that uses RunSignUp for registration and donations supports 7 different charities. They wanted to give runners the ability to donation some money to more than one charity at a time. We thought that was a good idea and added it!
(Also note the nice little rotating graphics of the different charities on the page.)
Do you have any good ideas for us that would make life better for you and others? let us know! firstname.lastname@example.org.