This tool enables the SBSettings and provides quick access to many other important device functionalities lіke connectіon іnterfaces, brіghtness and processes. Moreover, can be adapted to the user іnterface.
redsn0w works fine in the test with 3G. However, even after installing the software, iPhone still has the limitation of using the T-mobile SIM card.
As per the Apple dev team blog, redsn0w works with all iPhones of original types, original iPod touch,iPod touch 2G,iPhone 3G and iPhone 3GS.
To use redsn0w, upgrade the device in iTunes to firmware version of 3.0 and then run redsn0w to activate and jailbrake the device.