My summery of Android versions

• 1.0.
• September of 2008.
• 1.1.
• February of 2009.
• General software refinements, which I'll usually omit below.
• 1.5 Cupcake.
• April of 2009.
• Third party (custom) keyboards are now possible.
• We got widgets!
• Bluetooth A2DP and AVRCP profiles (think stereo).
• 1.6 Donut.
• September 2009.
• Voice I/O.
• Voice input (Speach to Text).
• Multi-lingual voice output (Text to Speech)
• Apps can make their data available to search results.
• Better support for gestures.
• 2.0 - 2.1 Eclair.
• 2.0 in October of 2009, 2.0.1 in December of 2009, and 2.1 in January of 2010.
• Support for multiple accounts in sync.
• Exchange account support for email.
• Camera app sucks much less.
• 2.2 - 2.2.3 Froyo.
• 2.2 in May of 2010, 2.2.1 and 2.2. in January of 2011, 2.2.3 in November of 2011.
• Dalvik VM gains Just In Time (JIT) compilation.
• Exchange support becomes USEFUL.
• USB and WiFi tethering. (Use your phone as a bridge between your laptop and your data plan.)
• Now have the option to DISABLE mobile data.
• Apps can now be installed to external memory (e.g. MicroSD card).
• 2.3 - 2.3.7 Gingerbread.
• 2.3 in December of 2010, 2.3.3 in February of 2011, 2.3.4 in ???, 2.5 in July of 2011, 2.3.6 in September of 2011, and 2.3.7 in ???.
• Native support for SIP VoIP.
• Selecting text to cut/copy/paste actually works.
• Text input cursor can now be precisely positioned.
• Ext4 replaces YAFFS(2) as standard file system.
• Native support for more sensors; gyroscopes, barometers, etc.
• NFC support.
• 3.0 - 3.2.2 Honeycomb
• 3.0 in February of 2011, 3.1 in May of 2011, 3.2 in July of 2011, 3.2.1 in September of 2011, 3.2.2 in August of 2011.
• Notification bar moved from top of screen to bottom corner.
• On screen software buttons (back, home, multi-task, menu, ...) and the action bar.
• View of recent apps can be snap shots (multi-task button) or existing icon view (long press physical home button).
• Browser UI becomes more like Google Chrome.
• Browser can now sync bookmarks with Google Chrome.
• Apps are now commonly multi-pane, e.g. message list and message body on one screen.
• More hardware acceleration.
• Support for multi-core CPUs.
• Encrypting user data.
• USB devices now work as expected, e.g. flash drives, game pads.
• Proper support for Bluetooth keyboards, gamepads, etc.
• Stock launcher now allows widgets to be resized.
• WiFi performance can be maintained when screen is off (WiFi locking).
• Apps designed for small screens can be zoomed or stretched to fit.
• this Android 2.2 feature is a really good thing and makes many reviewer's complaints about Honeycomb less of a big deal for normal people.
• Screenshots (or was this just a TF101 thang?).
• Previously required a custom ROM like Cyanogen Mod.
• Pasting integrated with 2.3.x selection UI.
• 4.0.1 - Ice Cream Sandwich.
• 4.0.1 in October of 2011, 4.0.2 in November of 2011, 4.0.3 in December of 2011.
• Small screens get traditional (1.0-2.3.x) UI, large screens get tablet style (3.x) UI from Honeycomb.
• On screen software buttons (from 3.x) now work on phones.
• Stock launcher catches up to common features of custom launchers.
• Access apps from lock screen.
• Previously required custom ROM/UI (e.g. Sense; Cyanogen Mod).
• Unlock your phone by taking a picture of your face.
• New Roboto font.
• Can now monitor data usage without requiring third party apps (or custom ROMs).
• Camera app sucks less.
• Basic photo-editing.
• Much stronger NFC integration, alternative to Bluetooth data transfer.
• Yet more work on hardware acceleration.
• WiFi Direct, a form of Ad-hoc WiFi networking and bridging.