I spoke with a "bug driver." His job was to drive a VW Beetle with a camera mounted on top. He drove up and down the streets of various cities for Google Maps. He said he drove at regular speed and captured near 360 degree images at 30 frames per second. Google whittled that information down to still images for easier Web delivery.
He also said that IMC captured the images for all of Google's street view except for San Fransisco, which was captured by a different company.
The camera they used was fairly small and light. Not only can it be mounted on a car, it can also be mounted on a backpack. They demonstrated this by periodically wandering the SIGGRAPH convention center with a backpack and showing the captured images.