Dead Man’s Switch is a service that, when you die, will send your passwords and other critical information to people whom you specify.
Your switch will email you every so often, asking you to show that you are fine by clicking a link. If something were to… happen… to you, your switch would then send the emails you wrote to the recipients you specified. Sort of an “electronic will”, one could say.
For all the hand-wringing about what happens to your digital possessions – email, pictures, videos, social network profiles, blogs, comments – after you die, Dead Man’s Switch’s solution is to leave that problem to someone else.
Update (6th October 2009): The Guardian has a feature on businesses like DM’sS.