Flickr added a new automatic upload feature to its to its iOS app on Wednesday, the service's latest effort to woo--and woo back--users in the ultra-competitive online photo-sharing arena.The optional feature will upload the 25 most recent pictures on your iPhone; after that all new photos will be automatically added to the service--all photos are uploaded on a private basis and made public only if the user chooses to edit and share a picture. The app can be set to do the uploads over cellular networks, or only when the phone has access to a Wi-Fi connection. (The app prompts users to turn on the automatic upload after it has been updated; users will have to go into the app's settings to toggle the upload parameters.)It's the latest effort by the Yahoo-owned Flickr to recover its ground in the photo-shar
