As the cat and mouse game between Apple and the jailbreaking community continues, another exploit has been discovered that will jailbreak the iPhone 4, iPod touch 4 and iPad. The exploit was found within the A4 chip bootrom, similar to that of the iPhone 3GS (old bootrom) exploit.
The exploit was discovered by p0sixninja, who originally planned to make the jailbreak available tomorrow, on 10/10/10 at 10:10 AM. The exploit will only work on the iPhone 4, iPod touch 4 and iPad, as they all use the A4 chip, but the team mentions that there will be future releases.
However, once the Greenpois0n team announced their ETA for their release, GeoHot suddenly came out of retirement and announced he will release a jailbreak on 10/11/10. After GeoHot made this announcement, he quickly compiled a jailbreak, using p0sixninja's exploit, and released it ahead of Greenpois0n, which is still slated for tomorrow, at the time of writing.
Limera1n works on the iPhone 3GS, iPod Touch 3G, iPhone 4, iPod touch 4, iPad on iOS 4.0, 4.1 and beyond.
GeoHot, aka George Hotz, is famous for his widely used BlackRa1n, which could jailbreak any Apple device at the time. Hotz was also the first hacker to successfully unlock the first iPhone, allowing it to work on any GSM carrier in the world.