Sneaking in a daily round or two of Doom might actually help you run your business better, says Lewis Paine of Opta Food Ingredients, in Bedford, Mass. The CEO of the $10-million company, which makes natural food ingredients, regularly indulges in sessions of SimCity (Maxis, 800-33-MAXIS), a computer-game classic.

SimCity challenges players to make executive decisions that affect an entire community. "For example," Paine explains, "if you build a housing development, you're going to have to build roads, and that comes out of the budget. SimCity allows you to see a multitude of factors, such as city planning and budgeting, not only quantitatively but visually."

How does playing computer games help him run a company? "It's a phenomenal teacher of how to allocate resources correctly and anticipate the needs that arise by taking one particular course of action," says Paine. "After you play a few times, you realize that you have to get better and better at anticipating the future impact of whatever you're doing now and really think through the allocations of the limited resources you have."