i paid $100 last december to get 50% bonus miles on all my flights up to 10k miles for 2004. i think they offered this for 2003 as well, but i did not participate.

i dont remember what it was called. if im not mistaken i recently read a post saying that you could still pay this fee and that they would credit all your past and future 2004 flights up to 10k total bonus miles.