SuperBoot creator PaulObrien[
SuperBoot - (Boot.img file) that when flashed will root your Nexus S running Android 2.3.3 Gingerbread.
The first time you boot (installing su and the superuser APK). No need to flash the system partition, no need to use ADB, no messing with the contents of your data partition, no overwriting the shipped ROM on your device, just flash the boot image using the instructions below and you’re done!
How To: Root Nexus S Android 2.3.3 Gingerbread using SuperBoot:
Step1: Before download, you need to check your device ‘about’ screen to determine which superboot version you need.
* Superboot for GRI40 – Superboot
* Superboot for GRH78 / GRH78C – Superboot
* Superboot for GRH55 – Superboot
Step2: Put your device in bootloader mode – Turn off the phone then turn on with the ‘volume up’ button pressed to enter the bootloader
Step3: Depending upon you OS follow the instructions as listed:
* WINDOWS – double click ‘install-superboot-windows.bat’
* MAC – Open a terminal window to the directory containing the files, and type ‘chmod +x install-superboot-mac.sh’ followed by ‘./install-superboot-mac.sh’
* LINUX – Open a terminal window to the directory containing the files, and type ‘chmod +x install-superboot-linux.sh’ followed by ‘./install-superboot-linux.sh’
The superboot image is also ‘insecure’, allowing you to use ‘adb remount’ as well as having full ADB root access to your device.
Note: If you are using a retail Nexus S, you may need to unlock the bootloader first, using ‘./fastboot-windows oem unlock’ (or the appropriate version for your PC).
Warning: OEM unlock sequence formats your device (including the internal SD storage!)
Source and credit: Technobolt