Since the introduction of the iPhone, SlingMedia has taunted us with news of SlingPlayer Mobile for the device. Even when the Sling app finally entered the iTunes App Store approval process of mystery, the delay of the app's release to the general public spawned talk of AT&T keeping Apple from approving the app.

With the iPhone approaching its two-year anniversary, SlingMedia has finally kept its promise.

After a few years practice on the Treo, Blackberry and other smartphones, it seems SlingMedia has learned that UI on a small device can make, or break, an app. Signing into a SlingBox is a painless affair and controlling the device via the iPhone is split between an easy to use D-pad setup for general navigation and a more robust Remote option that attempts to recreate the physical remote of your device. Options also include a useful Favorites feature where you choose your favorite stations for quick navigation. While the navigation is easy to use, because of latency issues, it's not exactly speedy. Tapping to change channels means stopping your video stream momentarily. Fortunately, when you tap three times during this lull, the app displays the number of taps and sends them to your home AV unit. We just wouldn't recommend navigating during the final seconds of the big game.

While watching TV over Wi-Fi on the iPhone--And for the release, it is only over Wi-Fi. More on that later--you can choose high quality and standard quality video or, if you just want to listen to the audio your show, an audio only setting. We didn't experience any hiccups while watching via Wi-Fi and surprisingly very few video artifacts. Of course a slow connection either on the SlingBox's side or on the Wi-Fi network you're connected too will determine your video quality.

The big drawback is that all of this depends on your ability to find a Wi-Fi hot spot. The pre-release versions of the app did ship with the ability to connect to your SlingBox via a 3G connection. The video cut out a few times and the quality wasn't on par with the Wi-Fi connection. But, even with those issues, we were able to enjoy a show while on the go.  AT&T released a statement stating that apps like SlingPlayer could create congestion on the network. Of course, congestion doesn't seem to be an issue with other phones on the AT&T network that have the SlingPlayer Mobile app. AT&T's claim to the fastest 3G network seems like a moot point when they're not allowing software that will run on it.

Another drawback is SlingMedia's recent announced that didn't plan to support legacy SlingBox devices for the iPhone app. After a small uprising on the internet, Sling now says that legacy devices will work, but will not be supported. Sling also warns that updates to either the Sling software or the iPhone could potentially render legacy devices completely useless with the iPhone app. We attempted to connect the iPhone to a legacy SlingBox AV and were thwarted by a pop-up that informed us that we should upgrade to a new SlingBox. Since the SlingBox AV isn't supported to work with the iPhone app, calling SlingMedia seemed like a waste of time. In other words, If you own a legacy device, you might want to save your money.

At $29.99 the SlingPlayer Mobile for iPhone is financially on par with SlingMedia's other mobile apps. Of course those apps work with legacy SlingBoxes devices and and over EDGE and 3G networks. Making it a pretty tough sell to iPhone owners.