GreenpoisOn Releases Untethered IOS 4.2.1 Jailbreak
The iOS 4.2.1 jailbreak has actually been around for a while, but unfortunately it came with a catch. If a person had to reboot their device, then they'd have to tether it to a computer in order to start using it again.
That presented a major inconvenience for a person whose battery might die while they were on the go and then wouldn't be able to use their iPhone, iPod, or iPad again until they got back to their PC.
This has made folks very anxious to get an untethered jailbreak that could survive a reboot. The good news today is that the untethered iOS 4.2.1 jailbreak was just released by GreenPois0n. The downside is it's Mac-only at this time, and GreenPois0n's site is currently offline. Those not wanting to wait for GreenPois0n to get back online can find the jailbreak tool at Bittorrent. Keep in mind that this will be the Mac version.
