Ian Burrell: Time to build a legacy now the big boys have arrived at Silicon Roundabout

Viewpoint: The Silicon Roundabout district has now grown to about 600 businesses

Google will this week announce plans for its seven-storey "campus" near east London's Silicon Roundabout. Twitter arrived in the area last year through its acquisition of the UK business TweetDeck and now Foursquare, the location-based social-networking site from New York, is moving into the neighbourhood.

The big boys have arrived. Unlike most of the snarled-up gyratory systems in the capital, there is a fresh momentum about Silicon Roundabout, a district around the Old Street Tube station which was first identified in 2008 as a group of 15 start-ups and has now grown to about 600 businesses.

The Government has rebranded the area as Tech City and is hoping that the London Olympics will provide a further catalyst. A "Start-Up Games" is being planned at which 300 international tech companies will compete – by pitching to a panel of experts – for gold, silver and bronze medals that be presented on a plinth overlooking the Olympic Park. "We are going to be showcasing the very best of the area," says Eric van der Kleij, Tech City's CEO, who points out that 20,000 journalists will be reporting from east London this summer.

According to Mr van der Kleij, this digital hub is unrivalled in Europe and stands alongside Silicon Valley and New York as one of the three great technology centres of the world. His enthusiasm is not universally shared, however. Olivia Solon, of wired.co.uk, which has reported that 50 US-based executives from companies including Microsoft, Google and Apple have recently decamped to Silicon Roundabout, is disappointed that none of the London companies have grown to become internet giants. "There is no denying there are lots of cool companies but none of them are growing at any terrifying rate – we aren't seeing the next Facebook emerging," she says.

The biggest success story so far is Moshi Monsters, the virtual-pets site, followed by the likes of the concert-tracking site Songkick, the business-card printer moo.com and the relatively well-established music site last.fm.

Jason Goodman, founder of the digital creative agency Albion, was one of the first of the tech arrivals in the Old Street area, nearly a decade ago. Albion has recently taken an additional floor in the Tea Building at Shoreditch and is providing desk space for start-up companies. He praises Mr van der Kleij for having taken Tech City beyond the realms of "political hot air" and gaining the attention of the bigger players. "It makes a big difference when you have the likes of Google, Twitter, Intel – these guys fund a lot of the networking and provide a lot of resources. They create certainty to the environment and lay longer-term foundations."

But Goodman compares Silicon Roundabout unfavourably to Tel Aviv's Silicon Wadi, which has benefited from two decades of Israeli government investment, including in specialist education. "They are delivering phenomenal developers and amazing engineers." He would like Imperial College and the London School of Economics to establish facilities in the area "with a specific focus on the web".

Google's Silicon Roundabout facility is likely to be based on research and development and also house workers from outside the company. "The arrival of the Google building will certainly boost the area's reputation and investment opportunities," says Harry Cymbler, founder of the digital PR and social media agency Hot Cherry. Silicon Roundabout could give east London a greater lasting value than those five Olympic rings.