PwnageTool 5.1.1 allows to create custom firmware and preserve modem version for unlock with ultrasn0w or Gevey. PwnageTool 5.1.1 supports all A4 devices:
iPhone 3GS
iPhone 4
iPad 1
iPod Touch 3G
iPod Touch 4G
Apple TV 2G
You can download RedSn0w 0.9.12b1 here and PwnageTool 5.1.1 here.
iOS 5.1.1 untethered jailbreak tutorial using Redsn0w is available here.
Here are step-by-step tutorials that will guide you through all the process of jailbreaking iOS 5.1 and iOS 5.0.1 with sn0wbreeze, redsn0w, pwnagetool and absenthe:
Just a day after PwnageTool 4.1.1 release, DevTeam created one more update for popular jailbreak utility – PwnageTool 4.1.2 for Mac OS X. This release should solve some problems that users had. However there are still users reporting iTunes errors when restoring custom firmware. Anyway PwnageTool 4.1.2 is worth trying.
iPhone 2G and iPod touch 1G do not officially support iOS 4. However there is a project called WhiteD00r that aims to bring iOS 4 functionality to iPhone 2G users with a custom firmware bundle.
This bundle is created by Matteo Morando and is based on firmware 3.1.3. It is built with PwnageTool. It incorporates several utilities to adds iOS 4 features such as multitasking, wallpaper, tethering, sms count, and more.
There are 3 different versions – Lite and Full for iPhone 2G and one for iPod touch 1G. Here is the complete feature list: