Hydrogen is slowly making its way into the public awareness as one of the up and coming green fuels that can save us from the stranglehold oil has on our world. As the most common element in the universe it's pretty easy to come by and when it burns with oxygen it produces only water.
As seems to be the way with a lot of these alternative fuel technologies they are gaining traction in Europe faster than in the US, partly due to the higher price of fuel and the denser population. Including the portions of Russia that are in Europe, it is roughly the size of the USA, but with double the population. Europe also has very little oil production capabilities and unlike the USA which produces 80% of its petroleum domestically, most of Europe's is imported. It's no wonder that Europeans are quite interested in finding cheaper sources of fuel as well as ones that they can produce domestically.
While there have been hydrogen cars produced in think tanks and for special purposes for some time, such as the Hydrogen busses that Iceland uses which have been running there for years now, it has still to makes its way into the mainstream. You cannot visit any dealership and make a choice between an oil burner and a hydrogen vehicle. You can't fill up on hydrogen at any nearby gas station (though Finland has a 'Hydrogen Highway' in the works with stations to fill up on H) and you certainly can't store it in sufficient quantities for your own use without some very specialized equipment and permits. 
Hydrogen 7
With all of that in mind it's not terribly surprising that in 2006 BMW introduced their plans for the Hydrogen 7. Many people have heard of 'Hydrogen Fuel Cells' which are units that burn Hydrogen and create electricity to then drive the car with electric motors. What most people are unaware of is that with minor modifications, the average car on the street could switch from burning oil to hydrogen with little effort. BMW had the same idea and its Hydrogen 7 runs on liquid hydrogen fed into a 12 cylinder internal combustion engine. The engine generates 260 horsepower and goes from 0-60 mph in a respectable 9.4 seconds. Its top speed is 143 mph which is electronically limited.
One of the big advantages to using a regular engine rather than a fuel cell is that it can also run on gasoline. In fact all the driver has to do is push a button the steering wheel to switch from hydrogen to gas. If either tank (hydrogen or gasoline) runs dry, the car automatically switches to the other. So if you're not in Finland, you'll still be OK.
As the name suggests, the Hydrogen 7 is based on the BMW 7-Series, the 760Li to be precise and has all the luxuries and amenities that buyers of a high-end BMW would expect. BMW knew that the price of any hydrogen vehicle would be high, and so they have tailored it to the tastes of people who can afford it. The vehicle is not a hand-built concept car, but is a regular production vehicle that is being leased in the US and Germany.
At launch fueling stations were available in Washington D.C. and Oxnard California with others coming online. A station is also open in Munich and at there are two in Berlin. There are dozens of fueling stations across the world now for Hydrogen vehicles, over 16 in California alone.
Though this is just the beginning, nations like Iceland which intends to be 100% oil free by 2050 are embracing this new technology and with further advances in systems that can extract the hydrogen from water and create fuel in a device roughly the size of a refrigerator, you could even produce your own hydrogen at home in the future and all fuel could simply be water, flowing through the pre-existing distribution systems.
We really can't help but give BMW credit by stepping forward with the first mainstream, fully functional Hydrogen vehicle that while it caters to the budgets of high-end BMW shoppers, sets the stage for regular production vehicles by proving a viable market.