Actually, the supreme court recently made a ruling that it is indeed perfectly legal to jailbreak and unlock iOS devices. On the other hand though, Apple still considers jailbreaking a void of your warranty and can refuse you the services thereof if they ever find that you have jailbroken it, but other than that, no legal ramifications. Of course, this also means that a person that wanted to make use of their warranty and had jaibroken could simply do a hard reset to get rid of the jailbreak data. Though that's assuming that your device is working well enough to boot up. Also, I'm not positive but I believe there may be an MC model jaibreak floating around out there somewhere on the internet (Google is your best friend)(Youtube too). To tell if your device is an MC model or not, got to Settings->General->About and read the first two characters of the line titled "Model". For example, mine is an MB model since, in "Model", it says "MB528LL".

In fact, I just Googled "jailbreak MC model iPod" and got what appears to be at least 2 or 3 viable methods right off the bat.

Oh, there are also instructions on Youtube. You can jailbreak MC model, you can jailbreak iOS 4.0 etc... Though avalability of a known jailbreak also depends on wether your idevice is 1st gen, 2nd gen,3rd gen, etc. Like I said, Google and Youtube are your friends.

Well, it's mainly a matter of preference. Especially if you don't have iOS 4 it allows you to get access to software to enable such features as app backgrounding, a background image on your app screen and more. Also, it's great for developers who want to take their code work with them. For example, I currently have gcc, Java, Bash terminal, and Python installed on my iPod along with all of the C standard libraries. I even have a custom boot logo and a custom charging battery graphic. In fact, my iPod's entire look has been themed to look like Mac OS X, my Safari app has been made to look something like Firefox (even has a Firefox icon for it's app icon!), etc. It also allows you to have access to <i>all kinds</i> of free, third-party software, tweaks to improve the usefulness/performance/looks of your iPod and it's UI, and other goodies.

I want to upgrade to iOS 4 but don't want to lose my jb. though I have caught wind recently of a program that claims to be able to, independently of iTunes, upgrade one's firmware without losing the jb data. it apparently does so by not re-flashing the NOR during the upgrade process. As to the error you keep getting, alexthesax, is there anything you can think of that might be causing it?