Last Friday we learned that Google was pushing an update to Android, version 2.2.1 or build number FRG83, to Nexus Ones. Several web sites provided instructions for how to download and install the update manually, though it was stated that it would be pushed via an over the air update. I can confirm that the update is happening over the air because my Nexus One received the update this evening. The update, which is only 3.9 MB in size, does not provide any new features to Android and Google says it includes important bug fixes and security patches. One of the fixes includes closing an exploit that enables Universal Androot to root and unroot Android phones.