From the main screen you can quickly update your location or see the last place you checked in from. The map has your location pinned, and is fully interactive so you can Zoom in/out or scroll around.

Fire Fone is a simple application to use Yahoo's Fire Eagle web service from your iPhone. You can post your current location from GPS/iPhone Location services, get the last updated location from Fire Eagle, and launch the Maps application with the Fire Eagle location.

In the settings view you can set Fire Fone to update Fire Eagle every time the application is launched.
You can also enter your Twitter credentials so your Twitter location is updated at the same time.

You can authorize Fire Fone with Fire Eagle from right in the application. No need to remember your access code, while the app launches Safari.