question about cycling

Okay, was just reading the advice Blue was giving Bryson re: his new tank. I am wondering -- if you get your biological filter started by obtaining filter media or gravel or ornaments from an established tank, but there are no fishes in your new tank because you are waiting for it to cycle, how do the bacteria survive? Remember, I'm the guilty person who swears by using the "Cycle" product! I was told that you don't use Cycle unless the fish are already in there, because the bacteria need to feed off the fishes wastes. So, if you add filter media from an established tank, but you have no fish, would not the same hold true? What will the bacteria survive on?