The Japan Broadcasting Corporation, or NHK, has developed a camera-carrying balloon capable of steady aerial shots that would previously have been done from a crane. The helium-filled balloon, which can rise to heights of 300 meters but would likely operate at 30 tometers, is attached to a four-axis gimbal that keeps the camera steady even when the balloon moves. Unlike a crane, the balloon is relatively cheap to produce and doesn't require a permit or large setup space. This means that it could be used to provide bird's-eye views of events that cranes couldn't reach, or new shots at things like sporting events.
Although the gimbal and camera can be remote-controlled to pan, tilt, or zoom, the balloon itself doesn't look to be mobile. If its tether is cut, however, it's apparently capable of bringing itself to a soft landing. The balloon is susceptible to strong winds, but not significantly more than some camera cranes — it can withstand anything up to 7 meters per second (around 16 miles per hour). You can probably also set any privacy fears to rest, as all you'd have to do would be look for the giant yellow dot in the sky.