They're good, as long as you keep them under an hour. The recommended time is 45 minutes ish, but who really keeps count, 'eh? You just kinda pass out, and then wake up three hours later with a puddle of drool next to your face. -.- Taking really long naps, though, is pretty unhealthy, because it screws up your sleep cycle, I've forgotten what the term for it is, and makes your nighttime sleep less er. Reinvigorating?
Ahh to live the life of my cat, my answer would be a resounding YES!!! Naps are really good for us. But you must determine what time is best for you, otherwise your nap can interfere with your sleep schedule.
So the question is....Are you a Lark or an Owl?
Determine who you are and when you should nap by going to Boston . com and search How to Nap? Such a good resource!