There was a great blog on the Laws of Software Development, and there were a few I saw as related to testing that I thought I should share.
Brooks' Law: Adding manpower to a late software project makes it later. Or testers, in this case.
Conway's Law: Any piece of software reflects the organizational structure that produced it. Good to keep in mind when testing.
Heisenbug Uncertainty Principle: Most production software bugs are soft: they go away when you look at them.
Hoare's Law of Large Programs: Inside every large problem is a small problem struggling to get out. Finding those small problems is worth searching for.
Lister's Law: People under time pressure don’t think faster. Or test faster.
Nathan's First Law: Software is a gas; it expands to fill its container.