In the heart of Yokohama, Japan Chinatown, you can get a fish pedicure for roughly $10 USD. They're a type of toothless carp that can live off decaying skin cells. The sensation is a light tickling.
There are some health concerns, but is generally considered safe as long you dont have any open cuts on your feet. The health concern is from sharing the water and fish with other people, not the fish themselves.