Steve has released the RC2 version of the Blacksn0w unlocks for iOS4. The RC2 version of blacksn0w is just a repackagedversion of the original iOS4 unlock released by geohot. The Blacksn0w RC2 also contains the binaries for 5.11.07 baseband for iPhone 3GS. The binary for 5.11.07 baseband was released by msft.guy a few days ago.
Use on Modem Firmware 05.11.07 ONLY!
V1.2: Support for 4.0 GM. Backwards compatible to 3.1.2/3 as well. V1.1: MyWi tethering fix
Geohot’s unlock for 3.1.2/3.1.3/4.0GM on the iPhone 3GS (and probably 3G). Please donate at http://blackra1n.com/ if you enjoy.
With 3.1.3 & 4.0 GM patch (when needed) by msft.guy. Packaged by Pushfix.info
This is an unofficial release but Geohot HAS given me permission to redistribute blacksn0w. All known issues with WiFi loss and boot loops seem to be fixed. If it doesn’t work for some reason, you should still get the SpringBoard. This allows you to uninstall if necessary. It is a little slower to boot because of the increased safety of the release. A 3GS boots to cell connection established in about 90 seconds in iOS 4 now (50% slower than 3.1.X).
Improvements may be made in the future.
The Blacksn0w RC2 unlock is only for iPhone 3GS on 05.11.07 baseband, with an old bootrom.
Here are the steps to unlock your iPhone 3GS running on iOS4.