Regarding the four forms of participatory culture, the one that I identified with most closely was the "Affiliations". I think this is because it was the idea of affiliations that drew me to the Internet in the first place. I first "wrote myself into being" on Facebook, and did so precisely because I wanted to be in the same social scene as the other freshman enetering Santa Clara.
I think this is the main reason youth begin to use the Internet, and once you gain a network on the web you begin to use the other more advanced skills of expressions, collaborative problem-solving and circulations that all expand from just being affiliated on the web. Affiliation doesn't require much action other than connecting with one group or another, but the other skills require some concrete contribution.