A debit card
Along with your checking account, sign up for a debit card. Make sure it has a Visa or MasterCard logo and can be used like a credit card.
Having a debit card can eliminate the need to rack up credit card debt for purchases, particularly purchases for which it is impossible to use cash or a check. Just remember that debit cards do not offer the same level of protection as credit cards, especially if your card is stolen and used fraudulently.