The Power of the People?

I'm a big believer in the power of the individual. But magazines and websites that generate endless lists of the "movers and shakers" in technology, politics, the arts, etc., are glorifying the individual at the expense of the other side of the equation: no individual can effect change without motivating communities.

Mel Gibson and Tom Cruise were once top box office forces. Then they behaved in ways that caused the masses to scratch their heads (or worse), and they saw their power erode. An individual is only as powerful as his or her ability to motivate others.

Seeing as we're in the middle of the Web 2.0 lifecycle, where's the list of the most powerful communities online? Is Digg's userbase really more powerful than Newsvine's? Does Facebook have more clout than MySpace?

How do you quantify that power?

And, what about this tricky variable: is a community more or less powerful when taking into account the exact individuals that community holds sway over? I.E., does being a Digg user automatically give you a louder voice because you have a marginal influence over Kevin Rose, rather than a more anonymous site creator?

What are your thoughts?

Also, here's hoping this concept gets picked up by someone whose community is more powerful than mine. ;)