As things turned out, it wasn't just about one phone - and Google wasn't the only company working on the project. In November 2007, the Open Handset Alliance, a consortium of 47 hardware, software and telecoms companies, unveiled Android, a brand new mobile platform based on the open source Linux operating system.
Because Android is open-source; the platform has many advantages for consumers and developers. Makers of smartphones and other mobile devices have more freedom to tweak the software to meet their needs, opening up a wider range of options.
A few makers have created custom user interfaces that run on top of the Android operating system (OS), morphing its aesthetics and usability. Android also allows vendors to create their own widgets. Perhaps the best-known example is HTC's Sense user interface. Among other innovations, this has a Friends Stream widget which aggregates and displays activity from your various social networks. Similarly, Motorola's MotoBlur interface features a widget called Happenings, which displays your social networking activity directly on your Android home screen. Other bespoke interfaces include Sony Ericsson's UX and Samsung's TouchWiz 3.0 and SLife (coming to Samsung phones soon).
HTC's Sense UI
Another advantage of open-source is that Android isn't tied to any single device, whether it is a phone, a netbook or a tablet. As we'll see later in this guide, hardware makers are squaring up to the challenge posed by Apple's incredibly successful iPad by building Android based 'slates'. As wen as the Samsung Galaxy Tab, which we contrast with the iPad starting on page 8, there are contenders from ViewSonic, Archos and Advent, plus a forthcoming Android-based portable entertainment device from Philips.
Hardware iterations for Android phones, meanwhile, vary a lot. The first models, such as the HTC designed G1, were almost purely touchscreen-based handsets featuring an admirably simple interface. The screens had limited resolution, however, and weren't especially responsive. But interest in the Android idea carried the day, and better hardware and new designs soon followed.
The next significant release, the Motorola Droid (known in the UK as the Milestone), was a hefty capacitive touchscreen model with a slide-out QWERTY keyboard, faster processor and responsive GPS module. 2010's big hits were HTC's Desire - at £20 to £25 a month, the first mainstream Android device - and the iPhone-rivaling Samsung Galaxy S, with its slim design and incredibly bright super AMOLED display.
In fact, whether you want a built-in keypad or a large touchscreen (or both), you can now probably find an Android phone to match your preferences.
Google unveiled version 2.3 of the Android OS, nicknamed 'Gingerbread', offering faster processing, better battery and application management and the intriguing idea of NFC (near field communications), bringing the prospect of using Android phones for contactless micropayments.
Our first impressions of Gingerbread on the Google Nexus S - an even faster version of the nippy Samsung Galaxy S phone that we like so much - were rather good. A 1GHz Hummingbird processor, a subtly curved screen that seems to cut the ear when you make a call plus remarkably smooth navigation and onscreen scrolling made us drool.
Android benefits from its dose ties with Google. Services such as Gmail, Google Calendar and Google search with voice (letting you speak what you want to find) are tightly integrated, and Android users get first dibs on Google apps such as Google Voice, Google Latitude, Maps Editor and Skymaps.
Users can also choose from thousands of third-party apps in the Android Market. Though this hasn't yet quite matched Apple's App Store in the number and quality of apps on offer, it's getting there. The Android Market stocks both paid and free apps that you can download directly to your device.
Unlike Apple, Google doesn't have a stringent approval process for apps, so developers can get their software into the Android Market faster and more easily. And, unlike the iPhone's App Store, the Android Market isn't the only place where Android users can get apps to run on their devices. Other sources include web-based third-party Android app libraries (such as AndroLib.com) and individual developers' websites. The choice is yours.
Research firm Gartner predicts that Android phones will become the second largest smartphone platform by 2012, right behind long-time industry leader Nokia. As Android software grows more refined, and as the variety of devices on the market increases, this prediction doesn't sound at all far-fetched.
Since its inception, Android has shaken up the mobile world - and that in itself is worth paying attention to.