I read somewhere, on a preschool site that I found off of a link on some one's web page (sorry I'd give credit if I knew where it went)...... that coffee and cornmeal mixed together make a good discovery center. (To read about our last center click HERE) SO we tried it.
I took one slightly sampled bag of coffee, Cinnamon flavor, and a bag of cornmeal an mixed it together and Wa-la a desert. Add a few lizards from the dollar store and you have school day entertainment. Easy.
The directions that I read somewhere said to use used coffee grounds, and I have some to add to it.... I just needed more cornmeal first. I wouldn't recommend using "good" coffee unless your like me and the only other option is to chunk it 'cause your hubby doesn't like it.
I would just take the grounds each morning and put them on a foil covered cookie sheet and let them dry. By the next day you could place them in a zippy bag and just keep adding to them as you can. Word of warning..... make sure they are really dry or else you will have mold growing as well....... :P.
I sweep the floor before hand so that what ever gets out of the box I can return to the box, with our to many foreign particles. ENJOY!!