Although the popularity of Android has grown quickly since its launch last year, it is still installed on less than 4% of the smartphones sold, and there are other free operating systems (Symbian, for instance) to which rival phone makers could switch.

Can Google have its Flan and eat it? We may not have too long a wait before finding out, because Kumar and other experts are predicting that the Googlephone will be launched in the US early next year.

One of Google’s challenges will be to link the phone to mobile networks so that the company’s services can be offered not just over wi-fi-connected broadband, but also over a 3G link to the internet, resulting in a real call-from-anywhere device.

This could prove a problem, though: few phone networks will appreciate being frozen out of lucrative business such as voice calling and text messaging, and being reduced to a simple data pipeline for Google’s services.

Google could also antagonise the networks by selling its mobile phone directly to customers and inviting them to use their existing Sim cards, whatever network they are on. “Google wants the Googlephone to be carrier-agnostic,” Kumar predicts. This could push the price of the handset to well over £500, because the cost of smartphones is heavily subsidised by networks, which recoup the money by locking customers into their services.

The real breakthrough, however, will come with the marriage of the Googlephone to Google Voice, the Californian company’s high-tech phone service. Google Voice gives US users a free phone number and allows unlimited free calls to any phone in the country — landline or mobile. International calls start from a couple of cents (just over a penny) a minute. Google Voice also uses sophisticated voice recognition to turn voicemails into emails, can block telemarketing calls automatically and offers free text messaging.

Google sounded its intentions two weeks ago when it purchased a small company called Gizmo5, which had developed technology to connect Google Voice with voice-over-internet (Voip) networks such as Skype. Now Google has the means to offer a complete, end-to-end phone service, with which consumers can make and receive calls between the Googlephone and other phones or computers anywhere in the world, and often for nothing.