Dust

This is one of the best time wasters ever. It is even more addictive if you are creative. Basically, you play around with dust. What makes this so fun? Each spec of dust has special properties specific to it. Using different components you can make, a volcano, grow a tree, make an ice rink(technically), make a seashore(technically), or even make a fuse to explode some fireworks. The best thing is that you can save it and retrieve it if you want. Enjoy one the most interestingly random things on the net!