I don't live in an urban area and expect the Eye-Fi Explore wouldn't work well for me. iPhoto '09 makes me very interested in geotagging, however. The ideal solution would be an SD card with built-in GPS. I suspect we're a few years away from that. In the meantime I'd like to see an external GPS device capable of communicating with a card such as the aforementioned for in-camera geotagging. I'm picturing a small, clip-on receiver which pairs with the Eye-Fi Explore to provide GPS data. Another possibility would be connecting via wi-fi or bluetooth to an iPhone app for real-time GPS data. Are you working on anything along those lines?