My 0.02BTC:
A billionaire investment in either mining or simply bitcoins themselves would be a waste of effort and money I think. For bitcoin to succeed it needs broad acceptance; not narrow. Regardless of how much capital that narrow acceptance has behind it. Either of these "investments" would do nothing other than make lot of other people a little bit richer (us who already hold bitcoins). And ideally we don't want mining under control of any one entity.
Better then is the philanthropic angle (and I believe it would be good non-philanthropically as well). Before bitcoin can be widely accepted as payment; merchants need to see that they aren't accepting some potentially worthless trinket-token. The way they can see that is from the exchanges. They provide liquidity and price-finding.
Trying to fight the legal system in the developed countries is an obvious nightmare, for a not-huge reward (relative to the size of those developed economies). Getting working exchanges in underdeveloped countries would be hugely beneficial; to bitcoin the project, but more importantly, to the country.
I really do believe that free trade has the power to transform. Bitcoin is the embodiment of the free-trade-tool.
Therefore if I had the ear of a philanthropic billionaire, I would be trying to persuade him to open exchanges in underdeveloped countries and put some PR and legal backing behind them. Kenya would be my first choice; then Nigeria; if it weren't for the insane political climates, Iran and North Korea would be good too. It's a bit late for Brazil (it's already doing fine on its own), but some of the smaller South American countries would benefit enormously from a solid bitcoin.
Here's the pitch then: "Rich western mobile company, Vodafone, has managed to become an integral part of the Kenyan economy. They've done it with their mobile-to-mobile payment system m-Pesa. They are a centralised private company and are charging relatively large fees to provide, essentially banking services to poor Kenyans. That centralisation gives them a discomfiting amount of control over Kenyan trade; and those fees are a yoke around the neck of people trying to dig themselves out of an economic hole. We could help them. Bitcoin is a decentralised payment system with minimal transfer fees. It can transfer value from any point on the internet to any other point on the internet near instantaneously. There is no single entity profiting from these transfers, and anyone can join in with the system that earns those fees, with no barrier to their entry. Using bitcoins as a method of transferring value is economically highly efficient. That efficiency can translate to profit. Even more so in the African continent as there are very few competing services.
Kenyan's need the banking facilities that we take for granted to grow their economy. Bitcoin would give them those facilities. It needs infrastructure and marketing investment to penetrate the market though. While that investment will take care of itself in rich countries, it is unlikely to in poor countries. For the first time in the history of the world, an African country could be ahead of the game. All it will take is to sow the seeds."
The biggest problem of course, is finding someone with the drive to push a project like this. I suspect that that, more than the money, is where the billionaire can help you. They must have access to lots of get-up-and-go people. Get one of them on board, and get them funded and I genuinely believe that Bitcoin could remake Africa.
many thanks for the positive posts especially the pitch here above & any further ideas along these lines would be most welcome, I'm wondering if the way to go may be to give the Africa, South America etc as examples of what could be done & that will probably develop naturally especially if the BTC price becomes more stable (say closer to the % daily/monthly moves in the gold price) & concentrate on trying to get funding for an obvious general good Bitcoin development project then ask the foundation which if any they may be more interested in backing - I shall also go & have a chat with my friend who already receives funding re this & her husband who's involved in charity & NPO work
edit: Bitcoin 419s coming to an email inbox near you soon -
I need your help to move my coins to $s with a bank/exchange in your country