While the term, “Web 2.0,” has been used to describe a wide array of applications and businesses that are often fueled by user-generated content and designed with many-to-many communication in mind, there’s one universal, operative word that sums up the essence of 2.0-ness: participatory.

But it’s not simply the case that all of this participating happens online in a virtual vacuum, where content is shared, accumulated, and archived without consequence. Participating online can also motivate users to participate offline.

As we’ve seen during this mid-term election season, videos posted to YouTube can and do affect public opinion–however fleeting that effect might be. And those involved in get-out-the-vote campaigns who aimed to increase young voter turnout this week through “>creative do-it-yourself PSAs like these now have some evidence that their efforts may have paid off.

Yet, according to a recent poll by Young Voter Strategies, it’s still good old-fashioned word-of-mouth and on-the-street campaigning that seem to drive young voters to the polls more than anything else.

So now, the question at hand for the next election: How do we interpret the impact when door-to-door campaigners use Web-enabled PDAs to show voters videos posted on YouTube?