I keep my computer in a cabinet, and I'm thinking of venting the cabinet with a 92mm or 120mm fan. I've got a few lying around, but I'd need to plug it in to a wall outlet. Should I just use an AC->DC ...

The incredible shrinking computer is about to reach a lower limit in size, with a new computer that's contained entirely within a wall-wart. Any smaller than this, and the computer would disappear ...