Not just corks...but cork flooring, etc. as well (which is amazing stuff to put in your kitchen...warm, acoustically insulating, soft and bouncy). Lovely stuff that.
we used to have a cork wall in my kitchen when i was a kid. very easy to post stuff on the wall with tacks and such. didn't think about the sound insulation side of things, it was just a gigantic cork wall to play with!
Do a search on google images for "cork products" the range is quite amazing. The umbrella is my favourite - waterproof and fireproof.