Like I needed another idea....
Found this website last night of all kinds of people who've made art out of pennies. The elephant is amazing. Now I want to mosaic something out of pennies. Don't know what yet. It would be fun to find a shape that was either suitable or ironic.
I remember seeing the mosaic wall on this forum, but wow, look at all the other things people have done too!
Here is a link that might be useful: Penny Art