Growth of Google (NSDQ:GOOG)’s Android platform has been nothing short of brisk, and this week Google advanced the ball further with the official debut of Google Android 2.2. Code-named Froyo, Android 2.2 adds tethering, faster speeds, Wi-Fi hot-spot support and a host of other improvements to Android, suggesting Google doesn’t plan to lose a shred of its Android momentum.Earlier this week came the latest report on global smartphone growth from Gartner, which said sales of Android-based phones increased by 707 percent in the first quarter of 2010 over the first quarter of 2009. Android phones were also said to have outpaced sales of phones runningApple (NSDQ: AAPL)’s iPhone OS in the first quarter, according to data from the NPD Group. Android phones were among the top-rated smartphones of 2009, and Android appears on several more released or slated-to-be-released smartphones this year, including the HTC Droid Incredible and HTC EVO 4G.

According to Google, the Android 2.2 mobile OS update will arrive later this year. Among the highlights described by Google at this week’s Google I/O Conference in San Francisco, here are five that make Android 2.2 shine:

1. Faster Speeds: According to Google, Android 2.2 is as much as five times faster than previous versions. That’s thanks to a Dalvik JIT compiler to boost CPU performance, Google said, and a JavaScript engine.

2. Tethering, Hot-Spot Support: As was heavily rumored in the weeks leading up to Google I/O, Android 2.2 includes built-in support for tethering and the ability to use Android phones as Wi-Fi hot spots. Questions remain about whether carriers of Android phones will charge users for the services, but they’re there for Android.

3. Flash Support: Android 2.2 is the first version of Google Android that can fully support both Adobe Flash and Adobe Air. Adobe is a key relationship for Google, and at Google’s I/O Conference Google Vice President of Engineering Vic Gundotra didn’t waste an opportunity to needle Apple and its very public war of words with Adobe.

“It turns out that on the Internet, people use Flash,” he said. “And part of being open means you’re inclusive, rather than exclusive, and that you’re open to innovation.”

4. SD Card, App Backup: Both are space-adders: Users can now install Android apps right on an SD card or using an Android phone’s internal storage. Another new function lets users back up and restore Android apps data.

5. Microsoft Exchange Support And Other Messaging Options: Lost amid a lot of the hype around Android 2.2’s most expected features was another nugget that might make Android phones more appealing to enterprises: support forMicrosoft (NSDQ: MSFT) Exchange. What’s more, Android now includes a cloud-to-device messaging feature that lets users more easily move information between Google applications on the Web and their various devices.