He has taken great care and time to list out and create simple CWM flash files for various tweaks that you can perform on your Nexus S device. They are all designed for MIUI ICS or ICS ROMS only though. A few examples of  what types of tweaks you can find are below.
- Init.d Scripts in the /system/etc/init.d folder:
- 08dalvik – Moves the Dalvik cache from the ext4 /data/dalvik to the faster yaffs /cache/dalvik partition
- 87calibration – Automatically calibrates the battery when flashing a new ROM
- 95zipalign – This is more enhanced zipaligning method. Its zipaligning the apps in the /system/app and /data/app. It also creates the database that contains infos on apps that are already zipaligned, and checks that databe on reboot. If all apps are zipaligned, it skips the zipalign process. Zipaligning is useful because it’s reducing the amount of used RAM
I would hate to steal his thunder and give you a full list of what can easily be found on his thread. He goes through all the various tweaks and what each one does. At the bottom of the thread you can find all the associated CWM flashable zip files for you to download. As with anything that is going to change, modify or tweak your device, it is highly recommended that you make a NAND backup before you apply anything. After all, they are provided for you to use at your own risk. Don’t blame us or Brainmaster if your phone explodes or eats your cat.
Direct yourself over Brainmaster’s thread for the low down and all the tweaks you can handle.
Source: XDA