1. www.radio.graden: You can listen to radio stations anywhere in the world.
2. www.mathway.com: A great site for students, it solves algebra, calculus and even chemistry problems!
3. www.freecampsites.net: If you live on the road, this could be useful. And yes, it is exactly what it sounds like.
4. www.myfridgefood.com: Just check off what's in your fridge and the website will spit out a bunch of recipes you can make.
5. www.archive.org/web: Find archived versions of websites from years ago. Also, on archive.org you can find a lot of other good stuff like books, movies, etc.
6. www.noisli.com: Generates background noise to help you while you study and work.