With most of my coins, I do as does JDiver and donate them at the airport, but I save some for souvenirs. I quite often find coins in hotel dresser drawers and am finding it harder and harder to use coins as even hotel vending machines often are in the higher spend range.

On a recent trip I picked up what will be the last of Canadian pennies just to have them.

When I get home I put them into Zip-loc bags maked with the country and date.