What's your Law? is a collection of "bit[s] of wisdom, some rule[s] of nature, some law-like pattern[s]" that leading thinkers were asked to contribute. The list included some of my favorite authors including Daniel C. Dennett, Richard Dawkins. Some of my favorites:

[Keith] Devlin's First Law
Buyer beware: in the hands of a charlatan, mathematics can be used to make a vacuous argument look impressive.

Devlin's Second Law
So can PowerPoint.

Rushkoff's Law
A religion will increase in social value until a majority of its members actually believe in it—at which point the social damage it causes will increase exponentially as long as it is in existence.

[As seen on ColbyCosh.com]