When you budget out your big trip, it’s easy to forget about transportation to and from the airport. It can really cost you if you aren’t careful. Fortunately, all of the world’s busiest airports have affordable options. These are the types of transportation you should look for if you’re hoping to save some cash.

It's easy to shrug off bus travel when you can fly, take trains or rent cars, but bus travel almost always has one distinct advantage: It's dirt cheap. If you're travelling to the UK any time soon, check out their bus routes. You can see a sizeable portion of the country for less than $US90 ($117) (not including airfare and lodging).

Not everyone who owns a dog has a car -- or access to ride-sharing -- to get their pup around, so they turn to busses and trains. If you find yourself considering public transportation to get your dog someplace, here's how to do so safely.