So far, this jailbreak only works with iPhone 2G, 3G and 1st gen iPod Touch. It’s also worth noting that this version of QuickPwn will not install Cydia on your iPhone. Instead, it will install Icy, a Cydia “competitor”.
I do not recommend using this jailbreak. As a matter of fact, I don’t even recommend installing the 3.0 Beta as it is still a little unstable and will most likely prevent you from unlocking in the near future. That’s just my opinion anyways and you are obviously free to do whatever you want.
You can download QuickPwn for 3.0 Beta 3 and read the QuickPwn tutorial for instructions.