Balance. Having any sort of hobby/interest that is physical and away from your desk is more important than you might think. Personally, I keep a garden and do home improvement projects, launching into one of these things tends to break the down cycle. Yours might be entirely different, but it also gives you a fresh viewpoint too. Think of it as a giant university, sometimes the guy down the hall in a completely different domain will have insight into what you're working on. You'll find building physical/meatspace things is not all that different from virtual.