Firstly, this should be noted that this application is not running in the background on your iPhone. It's a server-to-server agreement between AT&T and Loopt, so that you can always have location-based services working, and so people always know where you are. If you're into that kind of thing, then this is the application for you. We're sure that most of you out there are already using Loopt, so perhaps this is exactly the update you've been waiting for.
Loopt has announced the availability of the "Always-On" feature, which allows for Loopt to keep track of you while you are in motion, and to constantly update the information to the users who are following you on Loopt. The service is always optional, and you can turn it on or off at will. There are Push Notifications, so that you can get updated when something changes, but the Loopt application is not running in the background on your iPhone. Hence the reason Loopt is also mentioning that the service works while the application is not running on your iPhone.
The service is a test-run right now, and Loopt is offering it with a 14-day free trial. After that trial expires, users will have to pay $3.99 per month, plus any standard data and messaging rates you may incur on your bill. Once you sign up for the program, if you do not cancel on your own, you will be automatically billed for the service, so keep an eye on it if you try it, and it's not something you want to keep.