If you liked the tiled penny floor idea, then you'll love Michael's penny countertop. He says the project was quite easy and took approximately 6 to 8 hours to complete. He used about $77 in pennies, which, including his other supplies, came to about $7.50 a square foot. Cheaper than granite!
Complete instructions explaining how to tackle such a project yourself can be found over at Make. You can read more about the countertop at artifacturestudios.com.