rationalskepticism.org

Since Jesus was most probably put to death under Roman law because he upset Pilate - no matter what later Christians say - then I think that Jesus would be really pissed-off at people worshipping him depicted hanging from a cross at the moment of death. And not only that, a religion invented in his name with that self-same cross as its emblem would be anathema to him.

Link to a thread with a similar subject matter, i.e. crucifixion
Romans, Jews & Stoning