I noted with interest that in Australia there are no pennies and cash registers round up or down to the nearest nickel. Further, coins for larger denominations were usually smaller - so while the 50 cent piece is huge, the $1 and $2 dollar coins are smaller (about the diameter of a quarter and nickel respectively but about twice as thick). This makes a lot of sense - for example, if the government said they were going to do away with the 50 cent piece, everyone would agree immediately, they'd be so relieved they didn't have to carry them around anymore.
Not so in Canada where a proposal for doing away with the penny and adopting the rounding-off system is being submitted FOR THE THIRD time! I'm not sure why we'd want to hold onto the coppers. Here's hoping logic prevails and we can ditch them for good this time.