Skyscanner: This is a very good search engine for flights. It has everything you would expect from a search engine, but it also has some additional, very cool features. Instead of searching a flight to a specific location, you can search to ¨anywhere¨ and it will show what is the cheapest destination to visit from your home airport. In addition to this you can search for ¨all months¨ or ¨the cheapest month¨ and it will show you the cheapest month to travel to your destination.
Skiplagged: This is another cheap flight search engine, but this one allows you to take flights that other engines will not. Lets say you are flying out of ¨Paris¨ and going to ¨New York¨. Any web searcher will show you either direct flights or indirect flights to ¨New York¨. This web site will show you flights that are doing layovers, lets say a flight that goes to ¨Miami¨ from ¨Paris¨, but since you are only going to ¨New York¨ you just get out and ¨loose the connecting flight¨ Didn`t get it? go to the website and find out!
Hostelworld: This is anything you would expect when looking for a place to stay, anywhere in the world. You get hotels, apartments, great hostels, crappy ones, what ever you are into. Lots of cities, lots of people using it, and lots of reviews and feedback from other travelers that you might want to check before booking.
Airbnb: This is for those who want to get in touch with a place, by spending some time with the locals. Get to see their live styles, what they do, where do they go and how do they do it. You can book houses, apartments, rooms, leaving rooms, sofas and pretty much anything here, but it will always be through a safe website and in contact with local hosts.
Couchsurfing: This is the place to enter in contact with locals who are usually fellow travelers and you get to stay in their houses. Every host and every surfer gets reviews and this is how you now that it is save and what type of experiences you can get with each host or surfer you meet along the way. Go out there and catch some couches.
Hitchwiki: This is for the adventurer traveler. If you are a hitchhiker or if you want to tray it, this is the place to go to. This is a hitchhiking guide for the entire world. It is made by other people that are out there, on the roads getting rides. It provides information about countries, cities and about how to move around, and what to do or where to do it so you can get a lift.