Look here:
http://en.wikipedia.org/wiki/A_Thousand_Suns#Personnel (see the "Features" part)
But srsly, what the heck happened to LP!?!
They used to make pretty good Alternative Rock. But from their new album, literally the only thing I like are the Metalcore-like vocals on "Blackout". Now only if that song had some decent guitar...
They used to have some pretty good songs. "What I've Done", "New Divide"... even the last part of "In The End" was good enough to bear with the (c)rap in the first 1.5 minute. But now it seems they can't make anything good anymore
.