On YouTube, you may have noticed that the site's icon in the upper lefthand corner has been taken over by a .gif of PSY. If you follow that link, it reveals "YouTube in Rewind 2012," a playlist featuring the year's top YouTube videos in 2012.

There's also a mashup video mixing PSY's "Gangnam Style" with Carly Rae Jepsen's "Call Me Maybe," because the two are the most viral music videos for the year.

To create their top 10 list YouTube didn't just look at views, but looked at shares, searches, parodies, remixes and responses.

Top Trending YouTube Videos of 2012:

1. PSY - GANGNAM STYLE

2. Somebody That I Used to Know - Walk off the Earth (Gotye - Cover)

3. KONY 2012

4. "Call Me Maybe" by Carly Rae Jepsen - Feat. Justin Bieber, Selena, Ashley Tisdale & MORE!

5. Barack Obama vs Mitt Romney. Epic Rap Battles Of History Season 2

6. A DRAMATIC SURPRISE ON A QUIET SQUARE

7. WHY YOU ASKING ALL THEM QUESTIONS? .. #FCHW

8. Dubstep Violin - Lindsey Stirling - Crystallize

9. Facebook Parenting: For the troubled teen

10. Felix Baumgartner's supersonic freefall from 128k' - Mission Highlights

I originally found this story on Billboard.com