ONE CLICK I PHONE JAILBREAK

the Jailbreak Dev Team has released a one-click solution that you simply install through Installer.app. To use it, you need to have a jailbroken 1.1.2 iPhone , then it's simply a matter of tapping the install package and waiting about 20 minutes for the entire process to complete. Before installing, make sure you've set your Auto-Lock feature to Never, are connected to a Wi-Fi network (it downloads a 200MB image), and you've got at least 300MB of free space on your iPhone. Finally, check to make sure you've got the latest version of Installer.app before proceeding.

I haven't tried this method yet, but it should be scads easier than the previously posted method. As always, remember that things can go wrong, so proceed with caution.