currently both dns-servers pointed to by internic serving indymedia.org seem to be down.
here are some entries for you host-file:
72.232.204.178 chavez chavez.indymedia.org indymedia.org irc.indymedia.org ch.indymedia.org euskalherria.indymedia.org uk.indymedia.org www.indymedia.org synde.indymedia.org