In this case I’m upgrading an already jailbroken 5.0.1 iPhone 4S to iOS 5.1.1 using a Mac. The jailbreak and tools are specific, but I think that this process will apply to other iOS devices like iPads as long as a jailbreak for the iOS version you’re upgrading to exists.
If you are an Apple iPad 2 or iPhone 4S user, today brings great news. There is now an Untethered jailbreak for your devices. Detailes can be had at the greenpois0n.com website. It appears as though there is only an OSX version of the Jailbreak with Windows coming shortly. Check out details on this new release here. I’ll update as I find out more.