Finally the jailbreak for iPad, iPhone and iPod Touch from the Dev Team is available for download. It's free and untethered and it's called "Spirit". The jailbreak supports every iDevice with firmware version 3.1.2, 3.1.3 or 3.2.
If you have iPhone 3GS or an iPad you should backup your SHSH blobs before using the jailbreak. ECID SHSH or SHSH blob is a unique signature given to every Apple mobile device. When you decide to restore the firmware on your iPhone, iPod Touch or iPad, Apple servers checks this signature.
As you know, if a new firmware is released it becomes impossible to restore the older firmware from iTunes. But Cydia creator tuned up a new server and now it mimics Apple's verification server and saves your older SHSH blobs so that you can restore back your device to the older firmware. Without having your SHSH blobs saved you may accidentally update new firmware and then you not only lose your jailbreak but also won't be able to restore the older firmware to re-jailbreak your device.
This is also important because there is a big possibility that Apple will soon find out what exploit is used by the jailbreak and then it will be patched in the form of new firmware.
You can save your SHSH blob in three ways. Here is a guide to make it using AutoSHSH.
Start AutoSHSH and plug in you iPhone/iPod Touch/iPad in recovery mode (only one device at a time). Recovery mode launches when you turn off your device and hold down the "Home" button when connecting the USB cable. Then you must see "Connect to iTunes" message and logo on your device.
In AutoSHSH click on "Grab my SHSH Blobs Automatically". When the app will grab the signature you must choose whether you want to save it locally or not. Do not forget where you saved the signature. In the end of the procedure AutoSHSH will also upload it to saurik's server.
Plug in your device (it will be instantly recognized).
Hit the "Jailbreak" button.
Additionally here is a video tutorial for jailbreaking:
Please note that Spirit is not a carrier unlock so it won't allow you to use unauthorized wireless carriers. The jailbreak is also "sort of beta", so it may be buggy. DevTeam notifies that some apps in Cydia that are NOT designed for iPad may crash your system and require you to restore so be careful.