So according to a newsletter from iJailbreak.com here are the options.
iOS 5.1 Firmware: iPhone 4 – SEMI-UNTETHERED | iPhone 3GS – SEMI-UNTETHERED
iOS 5.0.1 Firmware: iPhone 4S – UNTETHERED | iPhone 4 – UNTETHERED | iPhone 3GS – UNTETHERED
iOS 5.0 Firmware: iPhone 4 – SEMI-UNTETHERED | iPhone 3GS – SEMI-UNTETHERED
Note: If you have an old-bootrom iPhone
Windows
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