I think the four-hour workday is an interesting idea. I'm still in school but I worked at a real estate development office for a summer, and most of those jobs could've been done in four hours a day if people didn't get away with being so lazy. I bet a lot of companies could reduce the workday to four hours, and if they're quicker to fire people for not making deadlines and such, they'd get exactly the same productivity out of them as they do now (plus, lots of people would probably want to work there).
If we all had a 4hr job day, then people will be getting 2 jobs. In a consumer markets, where how much you pay for housing determines the schooling of your kids, or the "want" for plasma tvs, nicer cars, more shiny things will make people work as much as they can.
The only way to enforce a 4 hrs work day will be thru law (goverment mandate not to work more than 4hrs a day, ala EU's 37.5 normal workweek),
Or, if something like that star trek machine that can create everything (you press a button, and food just comes out from it, or any electronics/material need you need).
Then people will be working only to teach, design new things, entertain, as material needs will be superflous.
The unfortunate thing about a 4 hour work day for traditional (read: non-technical) workers is that the advancement of technological tools allows them to accomplish the same amount of work in less time, meaning that if an individual (or entire company) wanted to get ahead, they would still use the entire 8 hours (arbitrary number. Many use even more) to accomplish much more work.
Technology hasn't shortened the amount of work we do, it has raised the standard for everyone to accomplish more.
This is mostly meant to apply to non-technical workers. People who deal with technology have a different and unique set of standards.
