We had already posted previously about how can you run iphone 4 facetime without wifi, you can either use 3G network signals to use facetime but for that hack previously you need to have a iphone 4, a laptop and a tethering enabled iphone which costs $15 a month.
But now a new iphone app called My3G allows you to use facetime on 3G network without any issues, My3G app allows users of any jailbroken iPhone to run apps that are restricted to wifi networks by making them think they are connected to wifi when only 3G is available. In addition to running FaceTime on the iPhone 4, iPhone users can also download podcasts and TV shows over 3G via iTunes or watch hi-def YouTube videos.
My3G is available to download from RockYourPhone
at a price of $ 3.99
. At the moment RockMy3G is available in RockYourApp Store
only, and this app is expected to be released on cydia appstore soon, so keep checking cydia new apps on your iphone 4
My3G is available on cydia for $2.79
under ModMyi repository
[ Source iHakintosh.com