In Snow Crash, there is a line:
First MetaCop leans her plank against the wall, ...
What is a plank?
A "plank" is a smart skateboard with high-tech retractable wheels and an on-board computer that works to prevent the board from impacting the ground if the user crashes. It also seems to prevent falling damage (to some extent) and allows speeds far in excess of classical wooden boards. Y.T's board has some storage space, a glass-shattering sonic weapon and a digital speedometer that doesn't work properly.
Y.T. has been privileged to watch many a young Clint plant his sweet face in an empty Burbclave pool during an unauthorized night run, but always on a skateboard, never ever in a car. The landscape of the suburban night has much weird beauty if you just look.
Back on the paddle again. It rolls across the yard on a set of RadiKS Mark IV Smartwheels. She upgraded to said magical sprockets after the following ad appeared in Thrasher magazine: CHISELED SPAM is what you will see in the mirror if you surf on a weak plank with dumb, fixed wheels and interface with a muffler, retread, snow turd, road kill, driveshaft, railroad tie, or unconscious pedestrian.
We also see them referred to as 'paddles'.