People new to open source software, blogging and other participatory Internet activities often wonder where others find the time. In short, it comes from not wasting a lot of time on things such as TV. The two-way nature of the Internet has made it possible for normal people to be part of the creative process in their spare time in a way that one-way media like TV and radio do not.
The article linked to above refers to the time wasted on TV etc as the cognitive surplus. It even goes on to define a ‘cognitive unit’ based on the total amount of work that has gone into creating Wikipedia. Using this unit, the amount of cognitive resources that are wasted on TV every year is estimated at 2,000 Wikipedias or 200 billion hours in the U.S. alone.
The linked article is worth your time. The suggested link between Gin, TV and societal change is fascinating.