Geohot has released blackra1n RC3 which now jailbreaks all iPod touches and iPhones (including iPhone 3GS and iPod touch 3rd Generation).
This jailbreak will not allow iPhone users to unlock for use on other carriers so if you rely on an unlock, stay with firmware 3.1.1.
For iPod touch 3rd Generation, the jailbreak is tethered so every time you fully turn off your device, you'll need to plug it back in and repeat steps 2-5.
- Make sure you're on firmware 3.1.2 by going into Settings, General, About, and then Version.
- Download and open blackra1n RC3:
Windows - http://theipodtouchproject.googlecode.com/files/blackra1n.exe
Mac - http://theipodtouchproject.googlecode.com/files/blackra1n.zip
- Plug in your device into your computer.
- Press Make it ra1n on your computer.
- Wait until the an image of a man with iPhone's spinning around him comes up. If you don't get the image, just restart your device, close blackra1n, and repeat steps 3 and 4.
- Once your device reboots, you should see a blackra1n icon on your homescreen, tap on it.
- Make sure you're connected to the internet, select Cydia, and tap on install.
- Blackra1n will now download and install Cydia, once it's done, Cydia will be on your homescreen.