Here's an intriguing essay comparing the origins of Jewish prayers and Christian prayers and how they have influenced each other. It's written by .
Here's my caveat: this article assumes that you're familiar with both Jewish and Christian liturgy. I think it's more likely that we don't know the other guy's as well as our own, lol, so we may have to help each other out. But it's still well worth reading. Just click for the link.