Thought this was a neat idea:
"Customers who sign up to the Save the Change scheme will have their debit card purchases rounded up to the nearest pound, with the difference deposited into a nominated Lloyds TSB savings account, enabling consumers to save unconsciously. This is ideal for people who don't carry cash but still want to have a coin jar".
Could work with other purchases or payments. Imagine if everything was priced in whole pounds or dollars - with the penny going to a charity/social benefit?