The British can make strong claims to the invention of the computer (Babbage) and the World Wide Web (Tim Berners-Lee) but examine the DNA of the modern world of technology and it's mainly American with a strong Northern Californian flavor. Ariba, Oracle, Google, Twitter - Silicon Valley born and bred.But it's not just Americans that are behind this innovation. This phenomenon has more to do with geography. Two of the most interesting innovators in the P2P space, Taulia and Tradeshift, although San Francisco based, are European - well their founders are. Why is it so important, indeed, is it important, for tech start-ups to have a Bay Area address? I was in San Francisco a few weeks ago and took the opportunity to speak to Christian Hjorth, Head of Sales at Tradeshift and Bertram Meyer, CEO of Taulia to understand why Silicon Valley is still important.