ok finally gave in and purchased the iphone 4 running with iOS4.2.1 - what method of jailbreak should i use? have a mac (on loan from a friend!) and a pc! never used a mac for jailbreaking however understand that there is the pwnagetool jailbreak - is this a tethered jailbreak? used redsn0w for windoze all my days for the iphone 3G however i understand that this is an untethered jailbreak for the iphone 4. not sure about greenpoison is this as good as redsn0w if not better?