The iPhone OS 3.0 has finally been unlocked for iPhone 3G users. The new code dubbed ultrasn0w was released late last night and can get you back to making phone calls if you got locked out after your last upgrade.
You will still need to jailbreak your iPhone with redsn0w first and then add a particular repository (not suppository thankfully)but once there you can install ultrasn0w through Cydia and you are golden.
Now we all wait while the mad geniuses from the DevTeam dive into the 3G S.
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1.Ensure you have upgraded to iPhone OS 3.0
2. Jailbreak your iPhone 3G using redsn0w or PwnageTool (this will also install Cydia/Icy)
3. Run Cydia or Icy
4. Please add the repo repo666.ultrasn0w.com to Cydia or Icy. That last "o" is actually the number zero "0"! If you use the letter "o" you'll get an error.
5. Search for 'ultrasn0w' in cydia or icy and install ultrasn0w
6. Reboot your iPhone 3G
7. T-Mobile USA users should disable 3G before using ultrasn0w