CyanogenMod 10 may only be a couple of weeks old, but it’s certainly making waves in the Android scene pretty quickly. Steve Kondik, the famed developer behind the custom build based on Android 4.1 Jelly Bean, has published preview builds of the ROM for the Samsung Galaxy S3.
This is (obviously) a very rough first version of the build, so not everything is going to work right. In other words, install at your own risk. Still it’s a step in the right direction towards putting a clean and well-regarded custom Android environment on one of the year’s best smartphones.
Go ahead and check the three XDA threads in the source link for each respective version. Just keep in mind that you need to have the AT&T or T-Mobile USA versions to use this ROM on the Galaxy S III. There’s no time frame for the International version as of yet.