iHear Network is a free mobile application for Android that lets you visit any location in the world and hear commentary from people in those locations as they post their experiences to the web in real-time.
Using a Google Map it is possible to let iHear find your current location or search for any location in the world. Once you have set your location the application then reads out the nearest geo-tagged content from Twitter. It is possible to adjust the radius of the area you wish to hear messages from. It is also possible to select to hear "New Tweets Only".
iHear is a great idea for a geo-location Twitter application. Using the application it is possible to zoom in on locations around the world, for example try Tahrir Square today, and hear the latest real-time Tweets coming from that location.
I can't help feeling however that iHear are missing a trick by not letting you sign-in with your Twitter account. It would be nice to be able to filter out the background 'Bieber' noise and just listen to the latest Twitter messages from my Twitter friends.