I currently have an iPod Touch 2nd gen (MB model) running iOS 4.0 jailbroken. I've never upgraded since I jailbroke, since I've read that it breaks your jailbreak. I searched around and it looks like whenever you upgrade, you have to rejailbreak the new firmware. Whenever iOS 4.1 is released, it would be nice to upgrade since it would make my iPod a little less laggy (I think it will anyway since it's pretty much the same hardware as the iPhone 3g, right?). I'm assuming I'll have to wait until either a jailbreak is released for 4.1, or wait until 4.2 is released and there's a jailbreak for that. Or can I jailbreak no matter the firmware since I've also read that MB model 2nd gen's are "pwned for life?" My main question is, how exactly do I upgrade? Do I just press Upgrade in iTunes and then jailbreak? Also, will all my jailbreak data be erased or is it just non-accessible?