In Germany I don't see how NGV vehicles help the overall energy picture, though they do produce less toxic pollutants. Whether it is oil or gas, Germany has to import. NGV vehicles would make more sense in places where gas is "stranded" - a long way from major customers - such as the Persian Gulf. In the rest of the world, gas should be reserved for heating, cooking, and fertilizer production.

Yup, peak oil is enough of a challenge without moving our transportation to NG and then facing a double whammy on peak gas.

I second Neil's comment. Shifting to an alternate fuel should only be considered when we have begun to become more responsible with our consumption habbits of petrol and are on the road to an alternative away from fossil fuels. NG should be a buffer to make the transition smoother and not be faced with a 1970s style shortage.

On that, if NG offers a 10 yr buffer post peak oil (soonish, if not now), and nukes offer another 10, we would be left with solar/wind or coal. Wind/solar cannot cover what we need in the short term until high density solar concentrators and ocean based wind/tide turbines become commonplace.
Coal will be worth its weight in oil 20-30 yrs from now because we still need to produce 1000 things out of it not related to fuel (in the absence of oil).

Not putting any bets on ITER either for an alternative for the next 40 yrs, as it is complex and large. Technology refinement and eventual delivery of a reliable 'plug and play lump' will take decades to deliver around the world, let alone the construction and commissioning time.
And who really knows the actual environmental and monetary cost of deuterium and tritium extraction from water, as well as the mainenance of the reactor. At this point engineers are just concerned with proving to the world that they can make a reactor that doesn't turn into a solid blob of molten alloy after 5 minutes.

In short, more money on solar and wind research. :)

NGVs looks great if you want to be a pollyanna or need to push industry propaganda, but if future NG supplies are viewed with the same skepticism as future oil supplies, the future isn't so bright: LNG trains are hugely expensive, hydrates have yet to be tapped and estimates of commerically viable resources vary wildly, bio-methane is great but won't be enough to replace the volume of fossil supplies already in use, coal is already highly in demand to generate electricity, many NG production areas have peaked, and so on. And then there are the CO2 emissions to consider. In America the NG picture is particularly unpleasant:

http://www.simmonsco-intl.com/files/ASPO2004.pdf

So I stand by what I said.