Requirements:
Wi-Fi internet connection
Jailbroken Iphone 3G 3.0 device
1. At the outset, toss in the repo repo666.ultrasn0w.com to Cydia sources. Subsequently, after writing the Ultrasn0w repo in the sources tap the repo666.ultrasn0w.com source until ultrasn0w pops up and at this moment install the Ultrasn0w unlocker.
2. Next, restart your iPhone 3G 3.0 in order for your spell to take effect.
3. Please bear in mind, for T-Mobile USA users you should put out of action the Iphone’s 3G flair before employing the ultrasn0w.
credit: Dev-Team