Download and extract this to any folder on your computer.
Run jailbreak.bat and everything should work on it's own.
Don't close the window, just be patient.
This requires you to be on a jailbroken 1.1.2 device with BSD Subsystem 1.5 or greater, and OpenSSH, connected to Wi-Fi.
Also, be plugged into some kind of power source, like the Dev Team recommends in the README.
Make sure you have lots of free space on your iPod too, you'll need it.
Thanks to the Dev Team for this method, darkphan for the SB patch, and everyone who tested this when it still had problems.
Some applications may not work on 1.1.3, but that's the risk you take.
Enjoy and good luck.
Updated:
Installer fixed
January pack installed by default
Mail fixed
Misc. bugs/slowdowns
Space issues fixed
Term-Vt100 fixed
This should do everything automatically for you, just like the Installer one.
Please report any problems in this thread, or look
here.