(1) Get $1M right now for doing nothing.

(2) Get $1M for every mile you swim across the English Channel. You need to start within 48 hours. The swim must be consecutive. The final measure will be the furthest point you were from the coast of England or France (whichever you started from). You can't have any support on the swim. You can tow behind you anything you want for safety or for the journey back (or onward across the Channel) after you're done swimming, but it can't help you on the swim. E.g., you can pull a rowboat with you for use after you're done.

Also: You 2x your money if you successfully make it across the English Channel with no support.

Which do you choose?

(http://www.autoadmit.com/thread.php?thread_id=5885800&forum_id=2.#50021722)