Pasta is one of my pet-peeves - or rather how all the info for them on the sides of packets is based on cooked weight - well I'd like to know how I'm supposed to weight the lasagne (pasta) once its cooked ........
Anyways, they do normally say how much uncooked pasta turned into when cooked - though you do need a calculator to work it out cos they normally do not use useful amounts.
I don't think there are too many things that differ that much (I cant think of any offhand), but its good to check on the nutritional info whether it states the amounts for uncooked or cooked - if there a big difference it should give some clue as to how to convert (though you may need a maths degree to work it out)