Well that was quick! Less than 24 hours after the public release of the iPhone 4 jailbreak, FaceTime has already been tricked into working over 3G connections. It's made possible thanks to My3G, a jailbreak app that tricks your iPhone into thinking it's on Wi-Fi instead of 3G. Besides FaceTime, it also allows you to lift plenty of other limitations like low-res YouYube videos or the 20MB download-limits on the App Store. With the jailbreak now being easier than ever, I feel like AT&T is about to have a very bad day.
Unfortunately, FaceTime is currently optimized for Wi-Fi connections and will therefore not look too great on 3G, especially if you're death gripping your iPhone. Also, the feature comes at a price, as you'll have to drop $2.99 on Cydia for it, or $3.99 on Rock (after a free trial). But, FaceTime over 3G might actually make it worth it and after all, that's what we've all been waiting for right?
Give it a try and tell us how it went in the comments!