Marco Arment has released an update to Instapaper adding Background Update Locations, a new feature that allows users to configure the app to automatically download new articles when a user arrives at or leaves specific locations. Using a technique pioneered by News.me, the new feature leverages the Region Monitoring API introduced in iOS 5 which allows third-party applications to perform tasks when users enter or leave a location. With Instapaper 4.2.2 users can add up to 10 locations and Instapaper will update automatically whenever the users arrive at or leave any of those locations. Arment notes in his blog that these locations are used only within the app itself and not shared or sent to Instapaper’s servers or any other web service. He also indicates that the use of the geofencing feature by Instapaper does not appear to have any impact on battery life on either the iPhone or iPad. Instapaper 4.2.2 is available from the App Store for $5. Background Update Locations requires an iPhone 4/4S, iPad 2 Wi-Fi + 3G or third-generation iPad Wi-Fi + Cellular.