You saw that study that Americans waste $1.72 billion in energy every year by leaving PCs on overnight? Are you part of the problem, or part of the solution?
I've been considering turning off my PCs off at night just to avoid wear simple wear and tear. As fans whir, they draw dust into your case, robbing heatsinks of heat dissipating power. And most hard drives aren't rated for 24/7 service these days. [The Register]