I was out today playing with a prototype GPS receiver from Garmin and Apple. From the website: "A GPSR with WiFi, Bluetooth, camera, 32GB Flash RAM, touch screen and buttons, on- and off-line browsing, and a special Geocaching Navigator style application for logging on and off line. The unit will also use a memory card so you can load maps and waypoints. All for $499 US."
Release date is set for April 1, 2008. I have mine on order.