To allow developers to "play around" ;) the iPhone Dev Team released a jailbreak for iOS 5 on the
iPhone4, iPhone3GS, iPad (1) and the iPod Touch 3G/4G.
The jailbreak is tethered means you need to do it every time your restart your device.
If you wanna keep your unlock STAY AWAY from it.
You can't activate your device with it (so you still need registered UUID).
PS: if you want a UUID registered contact me :)