Check these out! This company is putting together different GPS enabled apps for the iPhone/iPod Touch. They will be released with the App Store. Word is that they will work with the first generation phones/iPods as well... but I doubt they'll work quite as good.
http://www.posimotion.com/
G-Spot
The Compass:
Shows you what direction you are currently heading.
Spot Me:
A shortcut to pinpointing your current location instantly in Google Maps.
Also creates a log of most recent locations.
Share:
Instantly email your current location. The email contains a link that when clicked, takes you into Google Maps and shows your exact location. Friends trying to find where you're at? Hit "Share" and email it to them, they can pull your exact location right up and get directions.
Info:
Latitude, Longitude, Altitude, Heading, Speed, Accuracy, Date and Time of the most recent location update.
G-Park
G-Park in three easy steps:
1. Park your car and hit the Park Me! button.
2. Get lost.
3. Hit the Where Did I Park? button. Brings up Google maps and creates turn-by-turn directions that will take you right back to your car!
G-Park also provides an easy-to-use interface for additional details.
G-Life
Information coming soon...