We love this site because it is an excellent way to find the cheapest airplane tickets. You can even find the cheapest flights to anywhere in the world from your desired departure city by selecting everywhere as the destination.
This site allows you to check out your plane by viewing available seating maps and pics posted by other travelers. You can see which seats suck.
They make the list for the $9.99 a day weekend special that they sometimes offer at their local branches. You get 100 miles a day. Not a bad deal at all. They will even pick you up.
You can stay at 4 and 5 star hotels at a discounted rate.
Figure out where you may be staying before you book with hotwire or priceline.
If you find a hotel room at a cheaper price after you have booked, hotels.com will match the price.
Get a little bit of information about your destination before you go. Also, you can get any existing accompanying guidebooks.
This wiki is usually authored by the people. It offers all kind of info from getting around to things to do.
When hotel rooms are too expensive or you just want to sleep on a boat, you will want to check this site out.