LPT: Get rid of change in automated check-out machines

Next time you're at the grocery store bring a large amount of saved up change. As long as there is no one behind you in line, you can drop all of it into the machine free of charge. I've found that most machines will allow you to pay with both cash and credit/debit, so you can unload all of your spare change and then pay the rest with plastic, which insures you don't get any change back.