I haven't cross-referenced this idea with Wikipedia, so forgive me if I'm wrong about the thought that the Bible is one of, if not the most alluded to works of literature in literature.
Even in a public school (albeit in the south) I've found that students are more aware of Biblical allusions than any other. When I teach The Scarlet Letter, I actually pull out the Old Testament and read to them from the story of Daniel to show the allusion in the tapestry. Most kids are fascinated and think of the allusions as little "Where's Waldo's" in the books we read. Once interested, it is much easier to make them more aware of others in other texts.
And, like other posters said, I send them on Internet scavenger hunts to look up the source and get more details.
(Sidenote: I happen to be working on a Bible curriculum for the Old and New Testaments right now, and have found the historical allusions in the book of Revelation to be as interesting as they are insightful. For a text that is almost wholly metaphoric and symbollic, understanding the historical context of each of the seven churches makes the symbolism and language so much more alive. I think it is when we facilitate students in the understanding of the full context of a story that they learn to more fully appreciate literature.)