By Facebook :
To get the top trends, Facebook analyzed status updates across 236 countries, comparing the rate at which each phrase occurred in 2010 compared to 2009. The results above are the ones that had increased by both a large percentage and a large volume.
Trends that correspond to the most popular phrases on Google and Twitter in 2010 were the World Cup, Haiti, mineros/miners (referring to the trapped Chilean miners), the iPad and iPhone 4 and the inevitable Justin Bieber.
Facebook users also talked a lot about movies (in general), airplanes (referring to the song “Airplanes” by B.o.B. feat. Hayley Williams), games on Facebook, and, of course, the next year – 2011.
You can find some additional details about each phrase over on Facebook's official blog :
http://blog.facebook.com/blog.php?post=466369142130
By Twitter :
And Finally, by Youtube :