Popular mobile VoIP and chat client Fring has updated its mobile app to add support for 2-way video calling for the iPhone 4. You might be brushing off this feature because the new iPhone has FaceTime, but the Fring app has two big advantages over Apple's video calling feature: 3G support and compatibility across multiple platforms.

Fring launched video calls on iPhone last year, giving iPhone 3GS users a simple way to make calls, although 2-way video calling wasn't possible because the 3GS didn't have a front-facing camera. Earlier this year, the company brought 3G video calling to market.

Today's update finally makes Fring compatible with 2-way video calling on the iPhone 4. While it's easier to initiate or receive a FaceTime call, the company is betting that people will use Fring because it allows them to call friends without an iPhone 4 — one of the big restrictions to FaceTime. Fring's 3G connectivity also addresses another shortcoming of Apple's video calling feature: it only works on Wi-Fi.

Put it all together, and it means you can use Fring to call your friend with the Evo while you're driving across the country, though we don't recommend it for many reason.

Since FaceTime will eventually be an open platform, we hope that Fring will integrate FaceTime into its mobile apps, making video calls across multiple devices a seamless experience.