One of the first signs that told me the Internet was an unstoppable, world-wide phenomenon was when I saw a URL on a box of cheerios.
While shopping for jeans last weekend I saw written on a tag on a pair of pants "follow us on twitter at @blah, friend us on Facebook". I've seen enough of that to believe that social networking will also become an unstoppable world wide phenomenon. Its been consuming my world for two years now so I look for outside verification that its wider than my tech-centric world view.
After watching two revolutions, a line can be plotted from these two points. Another point along this line is wearable computing. Heads-up displays in sunglasses. Continual location tracking and body/environment monitoring. More pervasive and subtle forms of reputation on the Internet.
For years and years, AOL was successful in selling dial-up internet access long after DSL had arrived. The future was spreading itself out to those who get it on the second or third or four generation. 'standard' social networking, twitter and facebook, will continue to expand and their influence will grow.