The Process of pwning your iPod will actually modify your bootloader so you can run unsigned Firmware images, there's a small risk o(none if you follow instructions) however i'm not liable for anything that happens to your iToy, this is for "educational purposes only" That translates into allowing you to create a custom firmware, with every payload, repository or, boot image you want, and if you do that wrong you can screw up your iPod (never new of somebody) only if you don't follow instructions PROS - Unlike Ziphone (*cough* stolen code *cough*), iLiberty +, iDemocracy or any iProgram if you restore your iPod, you wont loose your jailbreak, (theorically ill explain that later), and you won't be in the need of re-jailbreak and start from scratch. - You can customize your Boot Images and restore ones -Is the Dev Team's Official jailbreak (dev team is the people who cracked 2.0, and 1..0 and unlocked the iPhone first, Zibri, Geohot they come from Dev Team) - Is the Most Stable Jailbreak CONS -can easly spot a jailbroken iPhone / iPot with the logos - Works only for firmware 1.1.4 and 2.0 (not all the betas, and haven't tried with 1.1.5)
http://www.instructables.com/id/PWNING-your-iPod-Touch-step-by-step/