Are using Web 2.0 yet?

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web 2.0 is the buzz word online. many people think its only happening now. But the fact it was out already. I have seen many websites are becoming more interactive with their visitors. If you look at message boards, would you say that is web 2.0 ? I would say yes a bit, its brings people together. If you look at some of the fire fox ext, that would also be part of the web 2.0..