^ On a sidenote, the site still exists though :/
But really when you're gonna update your iPod to a newer firmware, use TinyUmbrella to save your SHSH blobs.
Then you'll be jailbreaking proof for the future
I'll explain:
Apple, doesn't like people who jailbreak. Even though it's legal.
Apple has now made a new way to make it almost impossible to downgrade.
How?
By signing their firmware.
Example:
You're on 4.0 fw, a newer fw comes out, 4.1, you update.
In a few days, apples sign for 4.0 will be outdated (People at apple will do that, it's not a limited time or something)
You realise you can't jb on 4.1, you want to go back.
IMPOSSIBLE
Because their sign is out of date
What SHSH blobs do (not that I have the slightest idea how o.O) Is saving the old firmware, and tricking iTunes into believing that the sign is still legit.
And thus, you can downgrade.
So kids, save your SHSH blobs when you're about to upgrade
Good luck with not having a jailbreak