Here is how to put those pennies you have collected into good use: make a penny tile floor. For sure this would be your bragging right for years to come. This penny floor will also adds value to the entire house.
So how to make a penny floor? The first thing is to collect enough pennies. Then you need to put a lot of sweat equity into this project. Better have helping hands. But it is going to be a very fun project. Check out how it is done at a detailed house in the following link.
You can apply the same technique on your wall or counter top. Here is another great example.