Remote-control (RC) helicopters are smaller, quieter and much more nimble than ordinary helicopters, allowing them to take absurdly close-up shots.
In the sample video below, the camera nearly skims the surface of water between the docked boats in a marina near Fisherman's Wharf. It hovers with a bird's eye view over The Cliff House on the California coastline, too. Then it sweeps the city's skyline at dusk.
A company called SkyShutter has taken one of these RC helicopters and added a camera equipped with "gyro-stabilized remote-controlled gimbals," along with a live streaming video connection.