Create a simple WP plugin or some other script

I want to have the ability to add a special footer (with different) content to every page I choose. As of now the WP gives you an option to add one footer that would be the same o every page we want to have one section where we add the content of the footers and the ability to assign a footer to what ever post we like. Thanks a lot Btw- we are looking for a long term guy as well.