Before booking a flight, consider if the rate is cheaper if paid in another currency. Often budget airlines will make you pay in the currency of the country you're departing from, but this isn't always the case. An important note when doing this: make sure you're using a credit card that is free of foreign-transaction fees, otherwise your attempts to save money doing this will be lost! Our article on money matters for world travellers can help steer you in the right direction for the best credit cards for travel.
In Google Chrome or Safari, incognito is enabled by hitting Command (or “Control” if using PC), Shift, “N”. For Mozilla Firefox or Internet Explorer, hit Command (or “Control” if using a PC), Shift, “P”. This will open a new browser window where your information is not tracked, thus not inflating prices as you search. Note: if you're using an older version of OS X, open Safari then click “Safari” in the menu bar, and select “Private Browsing”.