Brit, this page is kinda interesting, if you're in to this sort of stuff http://en.wikipedia.org/wiki/Talk%3AAnnuit_CĹ“ptis

Thanks for the explanation Fatimah, that makes sense about the religious texts being omitted from money since its likely to become old and dirty and mistreated.

I always used to wonder why it's so rare to see deceased people on currency in Islamic countries, while in the west the opposite is true - most countries almost never put living people on money. I thought it may have had a religious origin.