Are you talking about these prickly brown demons that's falling off my tree? What is a large number?

What kind of art projects can they be used for?

Well what do you mean. Fresh ones or the fallen brown dried ones?
Those things are a giant pain for most people, care to share your secret of craft design with us?

Interesting request, Sandy. I am a flower show judge and make designs for flower shows. The more weird, the better. :-) I saw some last week in a sweet gum tree and thought what a great item to dry (green, of course) to add to a design in the future.
As you may know, dried plant material may be treated (painted, lacquered, etc) and used in flower arrangements/designs. My imagination goes wild with the thought of using those round balls/seed pods in a design.
Good luck in your hunt...
I'd like to know what you plan on doing with yours....

I have about 30 lbs to get rid of if you still want them email me ASAP

Well, growing up in TX they were sweet gum trees and I chewed a bunch of that gum. We used the pods in our forts as lethal weapons. I have seen them used glued on wreath forms, on baskets, on picture frames. We spray painted them in elementary school a silver or gold and hung from a nice ribbon for decorations on our tree. In fact I seem to remember seeing a book in print years ago that was all kinds of projects for dried seed pods. My DMIL collected all she could find when she came to visit.