It seems that the guys at Samsung really want to provide the best service for their current flagship, the Samsung Galaxy S2 I9100. They already have this phone on the list for providing an Ice Cream Sandwich update, but while they are working on that they have provided an update for the residents in Mexico for Android 2.3.6. This update is said to bring better boot time and increased performance compared to the previous version and some other tweaks as well. The update is currently only available in Mexico but it might become available in other countries as well. This update is available through the Samsung Kies software for unlocked handsets. Even if you don't live in Mexico, you can try to check for the update through the Kies software.