Few minutes ago Dev-Team has released iOS 4.3.1 untethered jailbreak for both Redsn0w 0.9.6rc9 and PwnageTool 4.3, the jailbreak support all iOS devices except iPad 2
NOTE: Users who rely on ultrasn0w unlock MUST stay away from Redsn0w.
Step 1: Download iOS 4.3.1 for your device (download links at the end)
Step 2: Update/Restore to iOS 4.3.1 firmware using the IPSW file via iTunes 10.2.1.
Step 3: Start Redsn0w and point it to the official iOS 4.3.1 firmware file.
Step 4: Now simply select “Install Cydia” and click “Next”.