Conceited Software/TouchFree has just released its GUI jailbreak. This is the "final bit" that performs the jailbreak after you run OktoPrep in 1.1.1 and then upgrade to 1.1.2. The Software runs under OS X and Windows, grabs the data off your iPod touch or iPhone, upgrades it with the Jailbreak, installs Installer.app and SSH.app, and reloads it back to your unit. The whole procedure takes about 10 minutes and after, you have a fully updated 1.1.2 jailbroken system.
You will need to downgrade to 1.1.1 if you bought a system with 1.1.2 already installed. This is discussed in the README.txt file in the zip and at the this jailbreakme.com webpage. This procedure is only for iTunes-activated iTunes and iPod touches--"hactivated" iPhones need not apply. That's because once you upgrade to 1.1.2, you'll need to be able to have a phone that's activated before running the program.
You can read more about my personal 1.1.2 jailbreaking in this earlier post.
Update: If you're missing the readline library (i.e. iPhuc doesn't work for you), you can download it here. Extract the zip to your Desktop, then in Terminal, type "sudo cp ~/Desktop/opt/local/lib/libreadline.5.2.dylib /opt/local/lib". You may need to sudo mkdir the /opt/local/lib folder first.
Update: Intel Only. (Thanks SmileyDude)