There is also a reference to the honey badger YouTube video uploaded by czg123. While hauling a load of bark, Alvin meets a creature and says "You're one of those honey badgers. You think you can just take whatever you want." In the video, Randall says the honey badger "just takes whatever it wants."
A reference is made to a YouTube video by Yosemitebear (http://www.youtube.com/watch?v=OQSNhk5ICTI). When the gang comes across a double rainbow, Theodore asks: "What does it mean?", Theo asks in a similar fashion to the video, at 2:44.
It was said at one point that the film would be in 3D, but for unknown reasons, it was charged to just a 2D release. Although it could have been just a rumor, there are several moments in the film where characters or thing fly close to the screen (such as in the scene where the chipmunks fight over a mango, or the final musical number.), like the film was meant to be in 3D.