You don't need a credit card to travel. Our culture, and the credit card industry, says that you need a credit card to have a great vacation. I am here as a living testimony that you can travel - and save money - by using a Debit card, cash, and good old-fashioned paper checks. We just returned from a GREAT vacation without using a single credit card.
I have also found some ways to save money while NOT using credit cards:

How we saved $160 while NOT using credit cards
Pre-paid a hotel room
Debit: Many hotel chains will offer a discount when making an advance purchase hotel reservation. We saved $20 by prepaying for a hotel we stayed in the first night of our trip. It was even less of a problem using our Debit card because everything was prepaid.
Avoided processing fees
Embedded in almost everything we buy is a 2-4 percent processing fee. The prices for things we buy at Target, the food we eat at Fazoli’s, and a movie at the theater have been inflated to compensate for this cost. It’s not the vendor’s fault, they have to send the 2-4 percent to the credit card companies.
However, we saved ourselves from paying a 3 percent processing fee by paying for our vacation via check. Every 2 months we would send some more money towards the balance until it was completely paid off. This saved us from a $150 expense that the horse ranch doesn't even get to keep - it goes to the credit card company!
It’s a great feeling to look back on the pictures and souvenirs that remind us of our awesome vacation. It’s even greater to know there won’t be a credit card statement showing up a few weeks later to remind us of how much we “enjoyed” the trip.
Utilize envelope system for food and dining out
Want to be certain to stick to your travel budget in these areas? Stuff an envelope with the cash you expect to spend. If the money begins to run out then it may be time to re-think the final meals (like Subway instead of a rib eye). You will definitely save money using a cash envelope than swiping a piece of plastic.

How we travel without a credit card
Planes, trains, boats and buses

Debit: We purchase plane tickets with our Debit card. Purchasing tickets online for airlines and even cruise lines is just as easy as using a credit card - but without the debt.
Cash or Check: While it is possible to purchase by Cash or Check, I believe it’s rather cumbersome (I won’t go into details because I’m not sure how it can be done).

Hotel or Destination locations

Debit: Don’t listen to the drama - hotels will take your debit card. They may post signs about holding a deposit for a few days, and this is true, but we have found a way around this. We prepay for many of our hotel stays. Once our schedule is put into place we shop hotels, look for the best deal based on our criteria, and often they will offer an advance discounted rate. The hotel we stayed in the first night of our trip was discounted by $20 because we paid two months in advance.
Check or Cash: Hotels will also take cash and some will still take a check, although checks are turned away at some check-in counters. My mother-in-law still pays for hotel rooms with cash. The clerk will ask to hold a deposit which is returned once the room has been inspected and no damages found.

Car rentals

Debit: Yes, the myth that rental car companies is busted! There are a few that will not accept them but I have heard from podcast listeners and friends that Hertz and Enterprise accepts Debit cards.

Budget Rental Car’s policy for Credit cards: They will place a $200 pre-authorization (hold) that is returned a few days after the rental has been returned in good condition.
Budget Rental Car’s policy for Debit cards: They will place a $200 hold (like pre-authorization) that is returned a few days after the rental has been returned in good condition. They may also run a credit check.

They sound very similar, don’t they? That’s because they are!