It really surprised us when there was no notification light already embedded into the Samsung Nexus S, and even more-so after we realized how dependent we were on it from the Nexus One (and countless other HTC devices). If you are up to rooting your device, then you can take advantage of the backlight notification integration (BMI) released by neldar from XDA Developers. Developer Morfic has ported neldar's work to the Nexus S and it seems to be working flawlessly.
This is not the standard notification LED we are used to seeing on many other smartphones, it is simply a pulsing of the lights behind the lower soft keys. Our very own Simms22 from the forums has uploaded a video of it in action, and can be found here. This modification is now embedded into both of Morfic's current kernals Honity12 and Honity14, so if you feel like giving this a try, tell us how it works for you! Be sure to download the BLN Control application from them market, as this is required for it to work properly.
[via AC Forums]