I have some styrofoam coolers--Will try this tomorrow!
Not steak boxes, but coolers from the cancer center, that
I got when Bill was sick. I kept seeing them stacked in the hall and asked what they did with the old ones. Threw them away---so I brought some home....

Pretty cool! And they would be so much lighter to lift and move around too.

The hypertufa forum is a great place for inspiration. I make hypertufa planters and faux 'tufa ones too. I prefer using latex paint on the styrofoam. I rough and chew them up with an electric carving knife before painting them. I tried the spray paint but didn't care for the melting/dissolving effect although mine didn't look as good as the ones in the link. I buy oops! cans of latex paint at the big box DIYs and Wally world.
They make great planters. I had a plant crack one with it's roots but that's been the only one. I actually covered the cracked one with 'tufa and kept using it.
Thanks for posting this!

I saw some of those in a magazine once and thought it was a cool idea (ok, pun intended!). Like Marlene said, they would be much easier to move around. Thanks for the link!

Neat!! I have a couple from a friend. Like some of other things she did also! Jan

HOW COOL IS THAT?!!!!!