Google is unveiling a new search tool to help you get the right information at the right time on your mobile device.

Called Google Now, the tool will be part of the next version of Google's Android operating system, called Jelly Bean.

Google Now and other Jelly Bean features will be available in mid-July. Some devices, including the Galaxy Nexus, will get the upgrade automatically over the air.

Google unveiled Jelly Bean as it opened a conference in San Francisco for computer programmers. During the conference, Google is also expected to unveil a small tablet computer bearing Google's brand.

With Google Now, if you say "traffic", for example, it will look at your usual commute to work and show you alternative routes if there's a lot of traffic. It will tell you the scores of your favourite sports teams automatically, and it will keep you up to date on flight statuses if you are flying somewhere. You'll have to activate Google Now to start using it.

Google. said the Google Now feature will get smarter as you use it more.

The feature bears resemblance to the Siri virtual assistant on Apple's iPhone.

Jelly Bean will also come with the ability to share photos by tapping two phones together, using an emerging wireless technology called near-field communications.

Google said there are a million new Android devices activated daily, up from 400,000 a year ago. Google says there's particularly fast growth in emerging markets such as Brazil and India. Android is now the chief rival to the mobile software running Apple's iPhone and iPad.

If speculation about the long-rumoured device pans out, the Google tablet is likely be seen as more of a threat to Amazon's Kindle Fire than Apple's top-selling iPad. More details should emerge during the opening speech of the three-day conference.

Like the Kindle Fire, the Google tablet is believed to have a seven-inch screen, measured diagonally - smaller than the iPad's nearly 10-inch display.

A Google expansion into the tablet market would bring another imposing entrant into what is already a battle of tech heavyweights. Last week Microsoft announced its own tablet, Surface. Expected to go on sale this autumn, it will run on a revamped version of Windows and compete directly with the iPad.

The new tablet is expected to be called the Nexus Seven, a reference to a line of smartphones that Google developed to run on its Android software for mobile phones.