I am new to the ipod touch and so am wondering what the advantage is that is desirable enough to do away with the warranty?
By Jailbreaking you can turn the device into what it should have been before apple restricted it.
Apart from customisation, you can apply tweaks and other utilities that allow you to exploit the device and install anything you want (within reason)
It is simple to do and opens up a massive range of possibilities.
It doesnt really void your warranty as if you have a problem it is a simple matter to do a restore before taking it to an apple store to get it fixed
by saing "before apple restricted it" makes it sound like you used to be able to easily customize and tweak your ipod etc. ...is this true?
I like the 5 icon dock vs. the 4 icon's you get without the jailbreak.
or the calendar lock screen (being able to see your calendar on the lock screen)
just little things like that.
those two things on it's own are worth it imo.