On Buying Silicon Valley
If one wishes to replicate the Valley's success and status as a startup hub one needs to mimic the ecosystem and support structures that have grown up around it, the angels, VC funds, (money) legal expertise, financial infrastructure (enabling infrastructure) and entrepreneurial culture (residual). The money and enabling infrastructure will accrete around the residual if it exists, quickly or slowly. Paul Graham has proposed that for US$30m-$100m this could probably be achieved in any US city fulfilling certain criteria, with greater or lesser likelihood of success dependent on the degree to which it fulfils them.
The money can realistically come from three types of sources, governments of whatever level, private individuals, or corporate bodies, profit-oriented or not, or some combination of the three, acting in concert. Given the electoral dynamics they labour under it is unlikely that any politician or party in serious danger of being out of power 10 years after the funds have been allocated would commit to this plan; and with the added proviso that all the startups funded should be at a minimum within an hours travel of each other on average only unitary municipalities would work, there being no US ~city-states barring D.C., whose freedom of action exists at the pleasure of Congress. The only US city that loosely fits this description to my knowledge is Chicago, given the iron grip of the Daley dynasty on the mayoralty.
What advantage would accrue to non-government actors who kickstarted this hub beyond the uncertain monetary return once the paper profits were booked? In other words, how can they capture as much of the value created by this new hub as possible? Given a long enough time horizon buying up property within an hour or so's travel of the chosen location would show handsome returns, assuming success. If we assume, I think conservatively, that 20 years would be sufficient for a hub to be mature, we have to ask who invests on these kind of timescales besides governments? Charitable foundations, university endowments, insurance companies and family offices, that's who. With the concentration of elite universities in Cambridge, MA, their great, if recently depleted endowments and the locale's current position as #2 startup hub of the US and thus the world, they might be able to equal the Valley, generate a handsome profit and prime the pump for future benefices from grateful students. Alternatively, anyone with a substantial portion of the minimum neccesary to fund could put said funds in escrow, not to be paid out until matching funds were committed by other parties. Or one wealthy individual desirous of leaving a lasting positive legacy to a city they hold dear could do it altrustically. Say, Warren Buffett for Omaha or Steve Schwarzmann for New York.
And outside North America? It would be easier to jumpstart a global city than somewhere with minimal legal or financial infrastructure but for $100m you could probably jumpstart a minor city of 500,000. The better the pre-existing institutions the bigger the bang for the buck.
Singapore A city-state run by economically literate technocrats who plan for the long term, with the rule of law, an educated workforce, good if not elite universities, and a liberal immigration policy. It also has form with the deliberate cultivation of expertise, e.g. it's biotech industry and the state holding company, Temasek's, investment in oil rig expertise despite the fact that it was unprofitable for over a decade.
China The CCP is not constrained by the unpopularity of targetting small areas for rapid development instead of spreading the pork around. Look at Shenzhen Special economic Zone, going in fifteen years from a fishing village to a manufacturing metropolis of huge importance to world trade. They could probably do it even if they did it wrong. Imagine a commitment of US$10m for each of ten years to competing Y Combinator clones, university backing as worthy gap years after a degree at Tsinghua or Peking, enticements to ethnic Chinese with Valley experience to come over, act as angels and VCs, etc.
Britain and Ireland
As close to being the USA as you get on the wrong continent, well, apart from Australia.
The only elite university in Computer Science is Cambridge, and it an edge case. With all of the EU and EFTA to draw upon for talent and no immigration restrictions, this is less of a problem than it seems. The money is there, whether private or possibly governmental. It seems likely that Labour is on the way back to the political wilderness for a generation, and throwing money at some Northern city, e.g. Birmingham would be a grand political gesture for a new Tory government, and possibly even a vote winner in the city. To my mind just doing it in Cambridge would be the better idea, but absent the University taking the initiative this seems unlikely.
Ireland is an unlikely candidate, but it has a reasonably competent industrial development agency and the experience of developing a second tier financial centre from nothing by careful planning and a devotion to tailoring a conducive legal environment. Dublin probably isn't quite dominant enough to be able to overcome the desire to spread the startups around which would defeat the point. Only here because I'm Irish. I suspect the Auctomatic lads would just say "Nah, no way"
Western Europe Luxembourg. Only a new, no account university, but fully able to draw on the surroundings, small enough that the entire country would share in the benefits, so the "Where's my pork?" problem doesn't arise, many many rich people and an establishment small enough that you might be able to get it done by talking to the right civil servant at a cocktail party. The expertise in crafting a conducive legal environment point from Ireland applies here too.
Berlin. City-state with a population that's a quarter non-German and you can get by on just English. Fantastic culture and surroundings, very good universities, internal migration magnet, cheap. Best European bet.
Zurich. Has ETH, world class university, easy for EU/EFTA citizens to get a residential visa, wonderful city. Switzerland's only disadvantage is the high cost of living. Ramen profitable would actually be a substantial barrier.
Paris, and it's suburb, otherwise known as France. My Economist reading sneer says no way, and the dirigiste tendency is strong, see the abortion that is Quaero, but if you could convince someone it would just be done. One very substantial disadvantage is the legal obligation that the working language be French.
Eastern Europe Romania seems to have a phenomenal over-representation in CS circles given its population, and Russia pulls its substantial weight. St. Petersburg would be my pick as the most cosmopolitan Russian city that isn't Moscow with its disadvantages (no parks worth a damn, expensive as all get out, but it shares that last with St. Petersburg)
Israel Much like Cambridge, MA, Tel Aviv is already a hub of note. The amount needed to prime the pump would be higher but again, a very good prospect if the funding was available.