Travel agencies used to be fundamental services for people who wanted to book a trip. Not only would travel agents filter through available flights for you, but they'd book your tickets, provide you with necessary travel information (such as maps or relevant brochures), and more.Today, websites such as Kayak and Google Flights do all that work quickly and for free. Additionally, travel rewards credit cards are enticing to travelers who can use them to book trips on the credit card's website to earn points and bonuses.