I suggest you to go over this list and I am sure you will some new useful website, which you haven't heard of. There were some in this list, which were a pleasant surprise for me. After all, there is only a limited I spend online everyday (Those who know me know that I am kidding).
No.1 on the list is GasBuddy. Even though MapQuest was first to bring Gas Prices link on their website, GasBuddy scored over them by bringing a more comprehensive and real-time update of prices, updated by their users.
Below are my favorites from this list:
2. Howcast: A video how-to site with a Wiki section for users to contribute.
6. Tripkick: Get inside information of various hotels. Which rooms are best, have best views, and which ones to be avoided. Now, you can make a specific booking request while making hotel reservations.
7. WikiTravel: Tradition of Wiki continues with best, concise up-to-date travel & tourist information.
10.Afrigadget:"a site dedicated to simple, sustainable inventions in Africa" per TIME.
16. RateMyProfessors: Yes, now students can anonymously rate their professors.
20.MapJack: A fantastic alternative to Google Maps. High-res photos of cities and very easy to
navigate.