Editor's note: If you look at the left hand side of this image, dated Monday, 11 December, you will see an iPod and a Belkin external battery pack velcroed to a panel next to the Discovery's toilet located in the Shuttle's middeck. The iPod is connected to a set of external speakers. This image was taken before Discovery docked with the International Space Station. It can also be seen in this image.
Image caption: S116-E-05405 (11 Dec. 2006) --- Astronaut Nicholas J. M. Patrick, STS-116 mission specialist, holds food packages near the galley on the middeck of Space Shuttle Discovery.
There is also another iPod (marked "PLT") velcroed to the upper right control panel on the Discovery's flight deck as seen in this image
Image caption: S116-E-05401 (11 Dec. 2006) --- Astronaut William A. (Bill) Oefelein, STS-116 pilot, occupies the pilot's station on the flight deck of Space Shuttle Discovery during flight day three activities.
Editor's 14 Dec update: According to NASA PAO: Six iPods also went up on the shuttle for the Discovery astronauts. The plan is (apparently) for the devices to come back with Discovery.
Several days ago I posted an image of an iPod that has been aboard the International Space Station for a while (see "iPod Sighting Aboard the International Space Station")