Jelly Bean is available OTA for the Nexus S now. And the manual links to download the official update file are here, too.
If you rock a Nexus S i9023 or i9020T you can manually get the 114MB file from the official Google-sevrers:
Update 4.0.4 (IMM76D) -> 4.1.1
Or via Mirrors: 1 - 2 - 3
Put it in your main folder on your device and start the reboot with the usual procedure to enter the recovery menu.Power off your phone and hold the "Volume Up" key while pressing the power button.Choose "recovery" via the volume up/down buttons. Then you see a triangle on the screen. Hold power and press "Volume Up" again. You will get a list of options.Select "update" and the update starts.Don't get nervous, don't remove the battery. Just keep waiting, it could take a while.
Do it at your own risk.
And then have fun with Jelly Bean. It tastes so good...
Update: Well looks like I completely forgot the fact that with 4.0.4, you can't just use the stock bootloader to flash it. Take a look here, but I didn't try. So, waiting for the OTA is an option again.
Update: Well looks like I completely forgot the fact that with 4.0.4, you can't just use the stock bootloader to flash it. Take a look here, but I didn't try. So, waiting for the OTA is an option again.