I'm a big fan of rock balancing, the art of positioning rocks, both large and small, in such a way that they bend the perception of what's possible. A well-balanced stack of stones is as unique as any snowflake and requires an almost-mystical understanding of placement and weight on the part of the artist.
Boing Boing writer Mark Frauenfelder found this video of stone artist Mike Grab at work balancing stones in Boulder, Colo.'s Boulder Creek after he saw Grab's work while picnicking nearby. Check out the artist at work.
Another artist, Scott Hocking, also works in stone but at a different angle. Hocking likes to meld his work with both the Detroit landscape, often of the bleak and abandoned variety. This work was done on the sixth floor of Michigan Central Station, now being renovated, and was found by Reddit user DrGonzo927.
Click over and check out his work.