The most recognizable form of juggling -- toss juggling -- involves using three objects (sometimes more) where they're systematically and continuously thrown up in the air so some objects are going up while others are coming down. But a slightly more complicated form of juggling -- contact juggling -- involves seamlessly manipulating balls along one's body instead of throwing them in the air.
This form of juggling was recently spotlighted at the 2012 Japan Juggling Festival held in Tokyo. As io9 explains further, contact juggling is where the "ball is rolled, tossed, balanced and bounced."
In this video uploaded to YouTube of one of the festival participants, not just one ball is involved though -- there are several. His performance is so intricate he won first place.
(Image: YouTube screenshot)
Watch the juggler:
National Geographic has featured contact juggling before. Learn more about this form of juggling in this clip: