Jason Fried of 37signals offers the following post:
What I especially like are the 4-day work weeks. It is a similar concept to Google giving you one day per week to work on your own projects, except the project is actually about making sure that you are fully rested and refreshed.
It is too easy to simply work more hours to try to get more done. I can relate to 37signals experiment because I find that my best work comes when I get plenty of rest, exercise, and spend time with my family.