Cyanogen have always had some of the best custom ROMs available. This time around, they managed to build the Android 4.1 Jelly Bean ROM. The ROM is built on AOSP, and is built specifically for owners of the international version of the Samsung Galaxy S2.
This ROM rite now is still in the alpha phase, so you will end up having some bug issues, and your device can be badly damaged. But if you are one of those people, who love experimenting with different ROMs, then go ahead on to the XDA Developers website and get the preview from there. Share your comments after using this ROM. Enjoy!