I obtained an iPad 1 from a relative who upgraded to the iPad 2. It is currently running firmware 4.2.1. Would the easiest way to jailbreak it to be to use a program like greenpoison directly, or upgrade it to 5.0.1 and then jailbreak it? Or maybe only upgrade it to 4.3.3 and then use jailbreakme.com? Also, if I jailbreak it, do I then never update the firmware again? I don't know much about this process. Thanks.