What's a peltast, you ask?
I like this picture and the peltasts themselves. They lacked armor, but were important enough to be used in the hundreds. I could see a story where the main character is a peltast on a campaign and has to survive hoplites, cavalry, other light infantry, even Persians. I also believe that the time period is another untapped vein for fantasy fiction, much like the early modern and modern periods. I know David Gemmell did a trilogy (well, more like 1/3 of one) before he died about the Trojan War, and Ben Bova wrote a novel about a Hittite warrior. There's probably some more that I'm unaware of, but much like Jello, there's always room for more!
Picture via Wikipedia.