I wanted to see if there was any further info on a CNG conversion for the Tundra. With gas prices the way they are now it may be worth it. The link below says a lot of cars in Utah are being converted to CNG because it is 63 cents a gallon. Of course it costs more in other parts of the county, but if the infrastructure is available in my area I'd consider it.
Natural Gas Cars: CNG Fuel Almost Free in Some Parts of the Country : Gas 2.0