Can you place your hand on the religious text of the religion you follow? What happens if you are an atheist?
Yes. There are all sorts of oaths you can swear, Capitalist.
My father's a judge so people are sworn in before him all the time. Muslims, for instance, swear on a Koran, but there have been problems in the past - you can't use a Koran that's been touched by a non-believer, so they have to be careful in handling it. I believe the strangest oath they have on file requires two live birds to have their necks broken, although I'm not sure that this one's been done in New South Wales courts yet.
Atheists just say they'll tell the truth, as far as I know.