If you’ve got an American Airlines AAdvantage account, you can earn 500 easy AA miles by updating your personal details at this website. (EDIT: link deleted as now dead)
The deadline for completing it is February 28th.
However …. read the small print before you do it. You are basically giving American Airlines and their marketing partner permission to sell your personal information to every Tom, Dick and Harry they can find. You cannot opt out of this.
Personally, I am not so desperate for 500 AA miles to do this. You might be, though!