Recycled rubber pavers from Home Depot. We did this and just love the way it freshened up the patio. It helped keep the heat from reflecting off the concrete patio into the back windows of our house, too.
How many everyday things can you use in your garden? ....or shop for at 2nd hand stores...I like it...I get something for the garden and still go shopping! Old heating vent covers as pavers in a garden.