The Samsung Galaxy S3, Samsung Galaxy Note 2 and even the first version of the Samsung Galaxy Note all have Android Jelly Bean in the majority of regions. However owners of the Samsung Galaxy S2 are still waiting to get their hands on the update.
Samsung Galaxy S2 Jelly Bean via Avatar ROM
There is some good news if you are in this predicament, if you cannot wait to get the update then you could get the Avatar ROM, which happens to be based on Android 4.1.2. This means that you can update your Samsung Galaxy S2 I9100G to Jelly Bean, along with enjoying custom features that come with the ROM.
Some of these include a themed engine of MIUI, along with CM10 customisation. As with any custom ROM you will have to root your device before you flash the Avatar ROM.
If you fancy having a go at this then you should make your way to Android Jinn and get instructions on how to get your hands on Jelly Bean 4.1.2 by way of the Avatar ROM for your Samsung Galaxy S2.