The Feature Cast song (called "Channel Hopping" originally) used to be available on iTunes. It's from the compilation album Straight Out the Cat Litter, Scoop 3. Unfortunately, the producers of the song did not obtain all the appropriate licenses for the sample clips they used in the song (specifically, the "hype the funk!" vocals and the random TV clips that play during the song's bridge). This was not realized until the song became popular through the iPod commercial. Legal action ensued by the legal rights-holders, and the entire album was pulled from stores (including the iTunes store). Months later, due to its popularity, Feature Cast re-recorded the song as "Channel Surfing" with vocals by MC Kool Keith. The new version is almost identical to the old version, except the illegal samples are no longer featured and the vocals are re-recorded. It takes a keen ear to tell the difference. The album was re-released with this version (now titled "Channel Surfing" rather than "Channel Hopping") in stores -- including the iTunes music store, where it is now available.