Jack Johnson
Jack Johnson, according to the Internet Movie Database
Jack Johnson sang the theme song in the Curious George movie. The song is called "Upside Down". There is a music video as well.
O Brother, Where Art Thou?
I would have to hear it again in the movie to be sure, but the hit version was by George Strait in 1989
Living in the Material World
Jack Johnson, according to the Internet Movie Database
Rainbow
Yellow Submarine The soundtrack to the Beatles' "Yellow Submarine" featured seven orchestral tracks by producer George Martin.
Goodnight Moon, Curious George, Green Eggs and Ham, Charlie and the Chocolate Factory, and A Wrinkle in Time.
Curious George - 2006 Curious George on Time Curious George's Bunny Hunt 1-5 was released on: USA: 13 September 2006
Curious George - 2006 Curious George's Rocket Ride Curious George Train Master 1-14 was released on: USA: 9 October 2006
Curious George - 2006 Curious George Discovers the Poles Curious George Finds His Way 1-10 was released on: USA: 27 September 2006
No. There is no indication that there will be a Curious George 3. Actually, I did find some web pages about the first Curious George movie and Curious George 2, but they still have not realeased a concrete announcement about a third Curious George movie.
Curious George - 2006 Curious George Takes a Vacation Curious George and the One That Got Away 1-22 was released on: USA: 16 January 2007
Curious George - 2006 Curious George Door Monkey Curious George Goes Up the River 1-7 was released on: USA: 15 September 2006
Curious George - 2006 Curious George and the Dam Builders Curious George's Low High Score 1-15 was released on: USA: 10 October 2006
Curious George - 2006 The Truth About George Burgers Curious George in the Dark 1-19 was released on: USA: 20 October 2006