Some Nexus S owners anticipating the update to Android 4.1 Jelly Bean have something to be happy about — the over-the-air update for the i9023 and i9020T hardware variants is beginning to be pushed out to users. While there doesn’t appear to be an official update for other variants at the present time, Android Police is pointing i9020a owners to a workaround discussed on the XDA Developers forum. If you're the kind of person that can't bear the thought of waiting for OTA notifications, you can also get the update right away from Google’s servers at the source link below.
OTA Android 4.1.1 Jelly Bean update available for some Nexus S variants
OTA Android 4.1.1 Jelly Bean update available for some Nexus S variants/
The Android 4.1.1 Jelly Bean OTA update is available for the i9023 and i9020T hardware variants.