The muffin cars, electric-powered vehicles built to resemble cupcakes, scoot around the open spaces of the San Mateo Event Center & Expo, a sprawling fairground about 20 miles south of San Francisco and, on this day, a million miles from normal.

Just inside the gates of the third annual Maker Faire, a converted fire engine belches an occasional explosive flare that sends a chest-pounding Pfoomp! throughout the fairground, startling bystanders over and over again. That contraption was made by folks from the Crucible, an industrial arts studio based in Oakland where people can take lessons in welding, blacksmithing and many, many other ways to play with heat and flame.

Nearby is the Swarm, a set of 30-inch cut-aluminum orbs that roll around on the grass, self-powered but guided by remote control. Children are playing keep-away with them.  Read More...