here... It was two layer with a tricot bonded "lining" fabric rather than the normal face fabric. Usually in white, or silvery-grey. Regular price is still pretty reasonable, at $8/m for 56" wide, see page 10 of their 2007 PDF catalogue.
I've used it for waterproof breathable lightly insulated sleeping bag overbags... Great if you want a light summer bag, to convert a 3 season down bag to very functional four season system, or to keep your down bag dry(er) in wet conditions.
As was said it CAN be used as a tarp but it'd be a waste and quite heavy. Better used as an "undercover" or supershelter/weathershield type system.
Also Goretex is 100% windproof, which can be handy in keeping heat in.