Here is one I cobbled up on my lunch hour.
Now, will someone check my math?
Could be helpful for picking sheets at the LHS.
You will need a good scale though!
Dave
Show your work for extra credit:
There's 1728 cubic inches per foot, 1 lb/cu foot = .00926 oz/cubic inch.

And now I see I listed it as pounds per foot SQUARED instead of CUBED, DOH!
The numbers are still valid though, just a little off on the description.
I KNEW I'd regret posting this.