Zillow.com recently launched an update to its eponymous iPhone real estate application, available for free here. The app uses GPS to find and follow users as they move through neighborhoods, and displays information on values, homes for-sale and those houses that have been recently sold. The upgrade sports a number of new features, including the addition of push notifications that take advantage of the capabilities delivered by the new iPhone OS 3.0. With push notifications, the app will notify users when additions or changes have been made to their saved searchesӣeven when the app isn't in use. Additional new features include the ability to search by price, bedrooms and bathrooms, and the aforementioned capacity to save searches and favorite homes.