So far the closest thing to this would be to hire someone else.

Methamphetamines, man.

Here you go: http://bit.ly/ZyFm

To increase the number of hours a day, make a watch with hours that last less than 60 minutes. This way you will work more hours in a day.

To make time flow slower, make a watch where hours last more than 60 minutes. That way you will accomplish more in each hour.

I prefer the second solution. Productivity is more important than hours worked.

People in other industries solve this sort of thing already. It sounds like some sort of drug would help accomplish this, but I have concerns about the health repercussions.