Inexpensive Cork Room Treatments

Had a happy discovery this week that inexpensive, egg-carton-waffled cork bath mats make great room treatments. They're 24" x 18" or 36" x 24", and the price of a couple of CDs. My wife bought an extra one, and I stole it to treat the wall behind and between my speakers with the result of a more focused center image and no hardness in the treble at volumes that previously over-energized my plaster walls. They'd be good at first-reflection points, too. Since they're a natural material, they don't look too bad either.
Amazon, where we got ours, sells the 24x18:

For the 36x24:,37-834,default,cp.html

Should it happen to be a bonus for anyone, it may be the world's first all-natural and recycled (old wine corks) room treatment ;).
Albertporter: If the walls of your listening room are moist, consider the problem solved.

Looked at the cork website.
I like the toed in aspect. Do they come with the rest of the body?
So--I can't believe I missed the cork soaker thing. Thank you, Albertporter, for putting my mind back in the gutter where it belongs.

Apart from that, the biggest problem I have now is not being able to fit my Vandersteens in my shower.
Those might help tame some high end reflections, but they won't trap any bass which is what most rooms really need most. That's where GIK traps rule!
True, it won't fix low frequency anomalies.
............And there is more to acoustic room treatments then bass and 1st reflection points.

"....GIK traps rule!"
GIK and many others. :):):):)
I use Echo Basters Phase 4 but there are many which work just as well or maybe even better.