This blog posting by Terry Gold, Founder, CEO, and President of Gold Systems, has however made me think differently about the need for vacations. It seems as if they are not something meant for "spoilt, no-care-in-the-world employee types" only.
If you only take a week at a time, I think you're only getting the mental benefit of about one day off. Think about it - the first three days you're still thinking about work. You get one good day and then spend the next three days thinking about going back to work. I think it takes two weeks at least, consecutive, with little or no thoughts of work to really recharge.
Your employees could probably use the break too, and they get to prove that they can run the business without you. If you must think about work, keep the thoughts big and bring back a good idea or two.