Earlier today we told you about the new redsn0w update coming soon, and it has arrived with pomp. The new Redsn0w beta can be used to hactivate iOS 4.0 for iPhone 3G along with jailbreaking iPhone 3G and iPod Touch 2G.
Once you jailbreak you device you can then unlock iPhone 3G running iOS 4.0 for baseband between 04.26.08 thru 05.13.04 using Ultrasn0w 0.9.3 from the Cydia store. The new jailbreak will also allow you to activate multitasking, wallpaper and battery percentage on the iPhone 3G.
Sadly iPhone 3GS and iPod Touch 3G users will have to wait for a little while more before redsn0w will be able to jailbreak or hactivate their devices.
Redsn0w beta is available for both Windows and Mac, download links for the same can be found here.