If you're planning to take a flight somewhere, I highly recommend using Google Flights to help. After you enter the locations and dates, Google Flights will display a variety of options from various airlines . You can see results for round trip, one way, or multi-city. You can limit your search by the number of stops, airline, outbound and arrival times, connecting airports, and flight duration. With the price graph, you can move your cursor along the bar chart to see the varying prices for the length of trip you want (e.g., 21 days). Once you've made a selection, Google will sometimes make suggestions in the results. For example, if it's cheaper to fly out a day earlier or to fly into a different airport from the one you selected, it will probably tell you that at the top of the results. You can also track prices for a specific date/location selection—if you want to get emails when there are significant price changes. Once you actually select a flight, return fli...