The title of the article says it all: Back 2 Basix (an Australian based wargaming company) is now directly selling high density extruded foam. The foam comes in two thicknesses: 25mm and 50mm. It can also be cut to size (length- and width-wise that is) from 2ft x 1ft down to 270mm x 270mm.
For all you scenery and board game makers here in Australia, this should be a boon! (Note they also sell in other currencies and ship abroad). I figure that these sheets are to go side by side with their battle frame series. This will enable a truly unique and modular series of scenery bits to be deployed by players. Although I've not seen many people purchase the battle frame series, this option is now getting more attractive.
Disclaimer: I'm not associated with back 2 basix in any way whatsoever, apart from being a previous customer of theirs.