From Wikipedia:

Around the Sun is the thirteenth album by the American band R.E.M., released in 2004. It is the first R.E.M. album to contain a title track. "The Outsiders" features a guest appearance by rapper Q-Tip, recalling a similar appearance by KRS-One on "Radio Song" from their 1991 album Out of Time. When performed live, Michael Stipe carries out the rap, as he does on a later b-side release of the song.
http://en.wikipedia.org/wiki/Around_the_Sun