A few months ago Bank of America started a program where they will transfer the the change from Debit card purchases from your checking account to your savings account at the end of every day.
For example say you spent $5.25 on lunch, then $.75 will be transfered. Now say you spend $32.01 on gas, the $.99 will be added to your $.75 and transfered as $1.74. In addition, for the first three months, they will match dollar for dollar what they transfer. After that it is matched at 5% a year.