For those of you who don’t already know, rooting your Android phone gives you full access to the file system. This will enable you to modify the phone’s firmware to whatever you want to have on your phone like skinning the UI, modding, overclocking CPU, flashing custom ROMs and so on.
Here is an image posted by well known Android developer clockwordmod, which shows Nexus S running custom Clockworkmod recovery.
Here’s the full how-to guide as posted on XDA-Developers forums:
First, reboot into your bootloader/fastboot mode. (Volume + Power Up, or adb reboot bootloader)
fastboot oem unlock
Then, install this recovery:
fastboot flash recovery recovery-clockwork-herring.img
Then boot into Clockwork recovery and install the Superuser zip file (adb reboot recovery, or from fastboot choose recovery):
To install a rooted/insecure boot image (adb has root):
fastboot flash boot rootboot.img
ROM Manager support is coming shortly.
Let the hacking begin ! [via Twitter]