Sign up to an organ donation registry

If you have a ghoulish bent, the idea of your organs kicking around in someone else's body after your death has to be appealing. If not, though, there are spiritual, medical, practical and golden-rule-al arguments as well. (And did you know that corneas can be donated?) If you're in the US, check out http://www.organdonor.gov/Default.asp. And UK would-be donors can visit

http://www.uktransplant.org.uk/ukt/how_to_become_a_donor/how_to_become_a_donor.jsp.

Effort involved: only a little. Most of the hard work takes place once you go.