The Nexus S has only been available to consumers for about two-weeks and we already have a simple one-click root solution thanks to Paul O'Brien (Mr. MoDaCo).
Paul has released a new Superboot, which gives users the ability to flash an image to give them instant root privileges. While there is a previously released ADB-based rooting method, this is ideal for people who don't want to get bogged down in something too technical. However, the one-click method still gives users who like to get down and dirty full ADB access to the system's files and folders.
This method works with Linux, Mac and Windows, but you'll have to check your phone's 'about' screen to see which version of Superboot you'll need.
If you're using a retail Nexus S you might have to unlock the bootloader first by using './fastboot-windows oem unlock' or the appropriate version for your computer. It should also be pointed out that the OEM boot sequence will wipe your device including the contents of your SD card, so backup any important data.
Here are the official instructions from MoDaCo. Caution, proceed at your own risk!
Before download, you need to check your device 'about' screen to determine which superboot version you need.
Superboot for XXJK8 – Superboot – DOWNLOAD (ROMraid Load Balancing) – MD5: 809a8e41ae8f0bb88b870cf1865aedff
How to use Superboot – Windows, Linux and OSX
– Download the Superboot zip file above and extract to a directory
– Put your device in bootloader mode – Turn off the phone then turn on with the 'volume up' button pressed to enter the bootloader
– 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'