how to remap the function key on my macbook pro?

hi, i have a 2.2ghz macbook pro, and currently running leopard. just a simple question, is there a way to swap the function key to ctrl and ctrl to function key on my macbook pro? cuz im used to international keyboards whereas the fn key is between the ctrl and alt key, so how do i swap it? any third party programs i need in order to do that? advise plz thanks