I need a Facebook application that kind of sit in the 'background' of user operations. Once the app is installed by the user, it will keep on sending the user's status updates, new friend connections etc to another web app of mine. It will keep on getting info no matter whether the app page is open or not.
My question is -- is this possible? So far, I've played around a simple iFrame app written with the Java API. It seems that it can only perform data collections whenever the page is hit.
EDIT: Privacy is definitely a valid concern here. But the application will definitely prompt for permission even if FB API is not built in to do so.
You can ask the user for the offline_access extended permission by using the fb:prompt-permission FBML tag: <fb:prompt-permission perms="offline_access">Can I have access to your data all the time?</fb:prompt-permission>, store the user's session key in your database and then query the Facebook API as needed. (You may need other extended permissions if there's other data you want to access that isn't a standard API call.)
Note that this isn't against the terms of service, but you won't be allowed to store any of the data you receive for more than 24 hours.