Redsn0w 0.9.6b5 for mac & Windows has been released which lets you to flash iPad baseband 06.15.00 on iPhone 3G & iPhone 3GS on iOS 4.1.2 or iOS 4.1 stuck at 05.15.04 & 05.14.04 baseband. If you planning to unlock your iPhone 3G/3GS running iOS 4.2.1 then you will need to download Redsn0w 0.9.6b5.
The good news is, unlike in PwnageTool 4.1.3, iPad 3.2.2. firmware is not required for redsn0w 0.9.6b5 it fetches iPad iOS 3.2.2 right from Apple serve. You just need to have stock firmware for iOS 4.2.1 for respective device.
Download Redsn0w 0.9.6b5 for Windows (run in Windows XP compatibility mode on Vista & Windows 7).
Stay tuned with us for how to update Baseband 06.15.00 using Redsn0w 0.9.6b5.