As part of the Democrats's Stimulus plan
LNG refueling stations are being subsidized by US-DOE funds,
and are supposed to eventually be roughly every 300 miles on US Interstates ... well over one thousand LNG stations are supposed to be installed.

The building plan started on the West Coast at the Port of Los Angeles and the 2nd facility was in Las Vegas, and I think the LNG facility in Salt Lake City is now operable.
More will be built heading eastward.
{I guess it is pure coincidence that both the money for LNG and the money for High Speed Train projects start in Pelosi's CA and go to Reid's NV}

UPS is running 59 LNG Kenworth trucks on a CA to NV route

http://www.usgreenchamber.com/news/ups-add-48-more-heavy-duty-lng-tractor-trucks-to-fleet/

It takes approximately 2% of the energy in methane to compress it to 2500 psi for CNG,
and it takes a greater 8% to liquefy methane to LNG.

One advantage of LNG is that it can take un-salable 'low grade' natural gas
(less than 1000 btu/thousand (edit) cubic foot coming out of the well)
that up until now has not been of high enough quality to sell to gas pipelines,
and turn it into a salable 1200 btu/mmcf pure methane in liquid form.

If you are interested in CNG and LNG
this taxpayer paid for National Renewable Energy Laboratory report in pdf format is worth a read:

http://www.afdc.energy.gov/afdc/pdfs/2451.pdf