Hidden Gems Of The Internet

So what do you know about the internet that nobody else does?

What tool do you use often that improves your day?

What site do you use rarely, but gives you great joy on each occasion?

It would be nice to have a collection here of some of the best and most useful things on the internet. To get the ball rolling I will add a couple of mine. Post anything you can think of, many might know about it, but you might make one persons day.

http://10minutemail.com/ -- The name says it all. It provides you with an e-mail address that will expire in ten minutes (or you can extend it for ten more) allowing you to sign up to a service without the spam.

http://giphy.com/ -- While Google implemented GIF search a while back, I find Giphy to be a nice browsing experience. (BONUS: Seen this GIF today and it made me smile)