The phone is Google's first official mobile phone device, built by manufacturer HTC, since it acquired mobile operating system company Android in 2005.
The phone is set to go on sale in the US, Singapore and Hong Kong initially and will later be rolled out in the UK. Nexus One will retail for around US$529.
Like the iPhone, Android offers fully integrated web-browsing and video applications with a five megapixel camera. The phone will offer 18,000 apps and unlike the iPhone, Nexus One allows multiple use of apps at the same time.
Users will also be able access Google maps, emails and aggregated contacts. A voice enabled keyboard has been embedded for speaking text messages, emails, tweets and Facebook updates.