Many people might disagree with that statement. But the truth is when you are travelling you're better off using a credit card. Maybe it's not so bad if you don't leave the US to only use a debit card, but if you travel at all internationally be prepared and take a credit card.
First you'll need one for surcharges on any hotel room. Now you can use a debit card but there will be a hold of maybe $100-$500 on your account because of it. Think not? It happens. And often these charges are not released for a few days. If you are an extreme budgeter this could cause your checks to bounce or payments to not clear. We're not extreme budgeters but I prefer not to tie up my cash.
Second the exchange rate on the credit card for foreign currency is better than what a bank will give you. I've tested it out and the credit card usually gives you 1-2% above the going day rate, but the bank usually charges you about 2-3%. And it does add up.
But what about carrying cash? Well sure it's nice to carry some cash, and absolutely necessary when travelling around the countryside of foreign countries. They don't use credit cards or debit cards. However, at that point you are better off going into a bank and exchanging US traveller's cheques than finding an ATM. We've been in the countryside of Asia and if they don't take credit or debit, ATM locations are just as bad.
Third, and what happened to us on our most current trip, if you buy tickets for a show or entertainment and it's cancelled, it's better on a credit card. You'll have an easier time disputing charges and getting refunds. We were told so by the people in the booth, that using a credit card would make the process faster, plus as foreigners we'd have protections in case the ticket booth wanted to charge us fees anyway for a show we never saw.
So perhaps a credit card isn't for everyone. However, I would not step foot of US soil and not take one. I've found it extremely useful, and easier to track my spending. As such, I have to go an reconcile our spending for our trip tomorrow.
Perhaps other avid travellers can share their experiences and debate whether they use a debit card or credit card. Most of our friends who travel extensively only use Credit Cards.