Greenpois0n RC5 for Windows! 4.2.1 jailbreak for all devices

Greenpois0n has finally been released! You can get it from http://www.greenpois0n.com/ if you have trouble with greenpois0n.com (You might because the servers are going to be hit hard), use ih8sn0w's mirror: http://mirrors.ih8sn0w.com/gp_win_rc5_b2.zip

Here's a tut (Taken from the readme provided with the download)!

1. plug the device to your computer using the USB cable
2. quit iTunes if it shows up
3. start greenpois0n.app
4. follow instructions
5. the device will boot a 1st time with verbose text on screen. This operation will install the jailbreak on the device.
6. the device will reboot normally
7. start the Loader application (green icon on the SpringBoard), and follow instructions to install Cydia