Rube Goldberg machines impress me more often than not. Here's a 70-step outdoor machine that covers a lot of ground ... all to put a basketball in a hoop. It took a month to create, and another month to get working.
via Creezy
I love stuff like this because it reminds me of life. Looking backward, you see how all the pieces go together. As you're going through it, it feels random and sometimes like you're moving backward or that your effort isn't directly contributing to your goal.
Nonetheless, it all comes together in the end.
Onwards!