Apple added another string to its bow this week with the acquisition of a mobile search service which pitches itself as a “virtual digital assistant”.

Siri is a US-based firm founded in 2007 by engineers and developers from Google, Yahoo, Apple, Motorola, Netscape, and eBay among others. The startup is venture-backed by investors including Menlo Ventures, Morgenthaler Ventures, The Li Ka Shing Foundation, and SRI International.

In February of this year, Siri made its official debut with an application catering to US users of the iPhone 3GS and the iPod Touch. It’s a voice-powered search tool that claims to understand natural language and can personalise results with greater precision over time.

“You can ask Siri questions naturally, just as you would ask your assistant, “Will it rain today?” or, “Get me a table at a good Italian restaurant.” Through the streamlined interface, you won’t have to weed through web pages to get movie tickets or call a cab. Over time, Siri will get to know you and, with your explicit permission, personalize your results,” the company blurb says.

At present, Siri claims to be proficient in the US for finding information on restaurants, events, taxis, movies, local search and weather, with more to come. As a result, it looks very much like Apple has added to its arsenal to better go up against Google.

Both Apple and Siri are remaining quiet on the acquisition and financial details have not been disclosed.

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