There's no doubt that Google's Android mobile operating system has exploded from its first foray in October 2008 to become--for many--the everyman's smartphone OS.

Google's breakneck development speed has paid off since it acquired Android, then a start-up, in 2005. The mature Android now accounts for 53 percent of smartphone sales as of the final quarter of 2010, according to research from Canalys--and there's no slowdown in sight. '

Despite an earlier promise that Android updates would be reduced from about twice per year to once per year, Google has recently released Android 2.3 (Gingerbread) and the tablet-specific Android 3.0 (Honeycomb), and hinted at the next treat in its enticing alphabet of releases, Ice Cream Sandwich. Meanwhile, many people are still waiting to see their Android 2.2 (Froyo) updates, some of which will no longer arrive.

Here's a look at milestones in Google's Android operating system, from its humble beginnings to its current ambitions in tablet domination.

mytable body { font: normal 11px auto "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif' color: 4f6b72' background: E6EAE9' } mytable a { color: c75f3e' } mytable { width: 620px' padding: 0' margin: 0' } mytable th { font: bold 13px "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif' color: 4f6b72' border-right: 1px solid C1DAD7' border-bottom: 1px solid C1DAD7' border-top: 1px solid C1DAD7' letter-spacing: 2px' text-transform: uppercase' text-align: center' vertical-align:middle' padding: 6px 6px 6px 12px' background: CAE8EA' } mytable .nobg tbody { border-top:none' } mytable td { border-right: 1px solid C1DAD7' border-bottom: 1px solid C1DAD7' background: E6EAE9' padding: 6px 6px 6px 12px' color: 4f6b72' } mytable th.spec { border-left: 1px solid C1DAD7' border-top: 0' background: fff' font: bold 11px "Trebuchet MS", Verdana, Arial, Helvetica, sans-serif' } Android version SDK release* Notable updates 1.0 (G1) February 2008 GPS and Bluetooth (but not stereo Bluetooth) Multitasking Tight integration with Google services like Gmail, Google Maps (with Street View), and Google Calendar Apps: Amazon MP3 Store' YouTube Android Market (about 35 apps at launch) No Microsoft Exchange Server' no camcorder 1.5 (Cupcake) April 2009 Universal search box (search had been limited to the Web) Revamped Android Market: Browsing categories (Apps, Games, Downloads) and filters (Top Free, Top Paid, Just In) Camera: Toggle between camera and video modes' integrated photo gallery and camera with bulk photo deleting SDK expands support for gestures, voice-to-text 1.6 (Donut) September 2009 Virtual, onscreen keyboard Camcorder mode for recording (and watching) video Stereo Bluetooth Home screen widgets and folders Copy/paste and search within the browser Direct upload to YouTube and Picasa 2.0 (Eclair) October 2009 Multiple user accounts Exchange support' universal e-mail inbox Quick Contact pop-up widget to launch communications with friends in the address book Search saved SMS and MMS messages Camera improvements include support for flash and digital zoom Bluetooth 2.1 Keyboard improvements: Adaptive dictionary that includes contact names in suggestions 2.1 (Eclair, second helping) January 2010 Live Wallpaper' five home screens Speech-to-text added to any text field' microphone icon for voice dictation in e-mails, texts, and so on 2.2 (Froyo) May 2010 Multiple user accounts Speedier OS USB tethering and hot-spot support Android Market update: Batch and automatic updates' installing apps to the SD card Adobe Flash 10.1 File uploading in the browser Improved Microsoft Exchange support: Security policies, global address lookup, calendar sync, remote wipe

Bluetooth support for voice dialing and contact sharing

3D graphics support

Gingerbread (Android 2.3) The Nexus S is the only Android phone to currently run on Gingerbread. Indeed, Android 2.3 included a few of the feature upgrades we expected, like support for video playback using Google's WebM video format. We also saw progressive improvements to copy/paste.

An online Android Market did arrive to shower Android users with over-the-air installations, but it came independently of the OS release cycle, and after the Nexus S debuted. '

Honeycomb (Android 3.0)We've taken several looks at Google's Honeycomb OS on CNET's top CES product, the Motorola Xoom. So far the tablet optimization impresses, especially when held up against other Android tablets running Android 2.2.

Google made its heavy investment in Honeycomb evident at its special demo event this month. There, The Goog showed off two-way video chatting with Google Chat and a new interactive app called Google Body that takes a Google Earth approach to human anatomy. CNET will have much more on Honeycomb when we get the Xoom in-house.

Ice Cream Sandwich (Android .) There isn't much known about Google's next Android release, not even a confirmation of the name. We're unsure if Ice Cream Sandwich will pick up where Gingerbread left off, as Android 2.4, or if it will follow in Honeycomb's footsteps as Android 3.1. It could roll out as soon as Google's annual I/O conference this May.

What about Google Music Speaking of I/O, we're also waiting for Google's Android Market music store to rival iTunes, something we've been looking out for since Google acquired Simplify Media. At this point, it's more probable we'll see Google Music announced and demoed there than at another special event like the Honeycomb demo.

Watch out, Apple. It's getting to be a Google World.

Update, February 7, 2011: Gingerbread and Honeycomb added.