|Origami crane (source)|
There are countless websites about origami and countless tutorials on how to make them. I find origami really interesting and fun to make. I mean just take a look at some of the things people make, it's amazing!
1000 paper cranes
There is a Japanese legend which says that if you fold 1000 paper cranes you get one wish. Since folding 1000 cranes is a huge challenge, people often work in groups to fold them all. This is known as Senbazuru.
Here are some websites with tutorials: