The Etys that mod is based on are pretty a pretty good sound for the money option. I personally hated the Shure EC2 (muddy bass and rolled off high end) for about the same price.
Another option that will be available soon is an iPhone specific canal phone (like the Etymotic and Shure) from Ultimate Ears. I got a set for beta testing today, and they sound REALLY good out of the box. Based on the state of manufacture my prototypes are, they have to be pretty close to production. They're based on the UE Metro.fi, which are their lower end models (they make serious audiophile custom monitors, too for mucho dinero). You can get Metros at Amazon for about $50, so I imagine the iPhone model won't be terribly expensive...