2010: A Year in Trends

YouTube Rewind 2010: The Year in Review.
http://www.youtube.com/rewind

YouTube have also launched Trends: a daily zeitgeist of YouTube.
http://youtube-trends.blogspot.com/

Google Zeitgeist 2010
http://www.google.com/intl/en/press/zeitgeist2010

Twitter 2010 Trends
http://yearinreview.twitter.com/trends/

Facebook 2010 Memology: Top Status Trends of the Year
http://blog.facebook.com/blog.php?post=466369142130