Google released the source code for Android 2.2, aka "Froyo", was released on Wednesday, and it's using an over-the-air update to load the new version on existing Nexus One phones.

"Today is one of those days that has my heart racing; we’ve just released the source code for Android 2.2," wrote Google software engineer Jean-Baptiste Queru in a post on the Android Developers blog. "Please don’t melt the servers down again while trying to download that latest source code."

Over on the xda-developers.com site, a fast-developing thread began right after the announcement, with sundry developers frantically searching impatiently waiting for the OTA.

According to some, the latest build will not work if you're already updated your Nexus One to a previous build. Over on AndroidSpin, developer Alex Smith writes: "It seems like some of us Nexus One users received an OTA update that updates the build number to FRF83. Unfortunately, if you are currently running the FRF72 update, you are going have to downgrade to FRF50 to install the latest build."

A posting on Android and Me notes that "A new over the air update began hitting Nexus One phones [Wednesday night] and it appears to deliver the official version of Android 2.2." The same post provides a link to the upgrade for users not wanting to wait for the OTA, plus helpful instructions.

Upgrades for other Android phones will follow. The just-released Motorola Droid X for example, is scheduled to move up to Android 2.2 in late summer.

While waiting for your Android phone to be Froyo-fied, remember the sage advice from one poster on Google's Android forum: "Everyone relax. You can't rush software. Well, you can, and it's called Windows Vista." ®