Instructions on how to jailbreak and unlock your iPhone 3G on iOS 4.2.1 firmware using RedSn0w for Windows. This tutorial will show you how to upgrade your baseband if needed for unlocking.
Comex has announced that iOS 4.3.1 and 4.3.2 will initially not be supported in his upcoming jailbreak due to time constraints, therefore users wanting to use the jailbreak should upgrade to iOS 4.3.3
The iPhone Dev-Team has announced that they will release updated versions of both RedSn0w and PwnageTool to provide an untethered jailbreak for iOS 4.3.1.
SemiRestore, a solution for iPhone, iPad, and iPod touch users who want to wipe their device clean without losing their jailbreak, has been updated for iOS 9.02 and iOS 9.1.