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.
Stains quite easily, though.
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!