It has been well-documented how the powers that be at AT&T neutered the SlingPlayer for iPhone application when it restricted its use to Wi-Fi networks only and stripped you of the ability to watch your SlingBox over the 3G mobile network. Finally a solution to the problem has been developed. It is called 3G Unrestrictor. This handy application allows you to set ANY application on your iPhone to work over the 3G network. The only problem is that this application is of course not available in the App Store and is available as a $2 download from the Cydia Store which means you will have to jailbreak your iPhone to unleash its full potential.
Here’s a demo of the SlingPlayer for iPhone working on the AT&T 3G network.