Primary Flight Display (PFD) on your Apple iPhone 3G
If you happen to fly and also call an Apple iPhone 3G your significant other, you might be interested to learn that i-hud.com has published a small software that turns your iPhone into a PFD.
This software uses the 3D accelleration sensors and the GPS-receiver that are built into the Apple iPhone 3G to derive the attitude, velocity and direction of the device.
Incidentally - but quite likely not coincidently - the primary flight display data display looks rather similar to what a Garmin G-1000 is showing on much larger displays.
This has me scratching my head in a big way, as it would be a very interesting gadget to add to my homebuilt IBIS canard airplane instrument panel. Ah well, it will still take a couple of years before I come to that and by then even devices like this one will have been improved upon 
As you can see, the information is displayed in crisp detail. Likely sunlight will interfere with readability though. The next bitmap shows the Apple iPhone / i-Hud PFD screen content in more detail:
Please note that this software does not use any pressure transducers connected to the static- and pitot ports, so all speed and altitude information that it presents is derived from GPS-data numerically. For these and other reasons, the Apple iPhone 3G running this software is not going to replace any of your other primary flying instruments, but otherwise it would have been a very nice backup device indeed.