If you are running Darky's ROM v8.0, you can flash the new Voodoo Kernel directly over the top and it works perfectly
You might wonder what the point is of flashing a new Kernel since Darky's runs so well 'out of the box' ? Well the main reason is the new Kernel's effect on the Galaxy S regarding sound output. If, like me, you use your SGS as an mp3 player you will know that the sound output through the earplugs is acceptable but not much more. You will not believe the difference this Kernel makes! The difference (soundwise) between this and the stock Kernel is like the difference between JG1 and JPY firmware!
The default Kernel that comes with Darky's v8.0 is '18.104.22.168 wasted@box #8', after the upgrade the new Kernel is '22.214.171.124 curio@carton #voodoo_stable_5.1'.
The author of this Kernel (Supercurio) is the guy behind the Voodoo lagfix and indeed the Voodoo version of Clockworkmod recovery which we all know is the recovery to be seen with
EDIT: Darky has decided to use the speedmod kernel in v8.1, but this new choice still includes the same Voodoo sound implemention
The Kernel works in conjunction with a (free) app called 'Voodoo App' which can be grabbed from the market. The audio output is a lot fuller, richer, crisp with plenty of bass frequencies, I can't stress enough how much better it is. This isn't all the Kernel does, but it's the main reason I installed it
More information is AVAILABLE HERE along with the download links for the CWM and Odin versions of the Kernel.
The Voodoo App can be found RIGHT HERE.