Don't bike or skateboard on me!
Much of the skateboarding in Davis happens at the Public Skate Park. Technically, skateboarding is illegal on the sidewalks downtown, as the stenciled warnings will remind you. Skateboarding is also specifically outlawed in Central Park and around the Senior Center.
Although grinding and "reckless skating" are officially prohibited on the UC Davis campus, such rules don't stop the school from being another popular destination for advanced skaters and even pros. One seven-step rail has become relatively well-known among hardcore skate fans, and several pros have been known to grind it when visiting the area. Here's a YouTube clip of local pro Nyjah Huston taking it on. Other locations that people often skate at include the steps in front of Physics and Geology, Chemistry Building, Roessler Hall and Bainer Hall. Andrew Reynolds made Roessler Hall famous when he kickflipped the 28 foot "Ivy Gap" as seen in his "Stay Gold Part" One can also find skaters hanging out around Central Park, despite the ordinance that prohibits skating there.
In addition to the famous "Davis Gap" another spot located at Kleiber Hall. It features a 13 stair, hubba, and rail.
Kleiber Hall Stairs
Much of the hate for skaters comes from how they can destroy property when they wax edges and grind on things that weren't meant to be ground on. Therefore some would prefer that skaters keep their grinds to the skate park even if it means stifling creative uses for mostly pointless and ugly architectural elements. Of course, grinding on and waxing these "ugly" architectural elements makes them even uglier, pissing off property owners and people who dislike eyesores, perhaps inducing even stupider laws against skateboarding.
Skateboarding and longboarding (longboards tend to have larger wheels that handle cracks and rocks better) are popular alternatives to biking around town. Boarding is maybe not as fast as biking, but it's often overlooked as another practical and green form of transportation. For some of the folks who are car-free in Davis, skateboarding serves as a primary form of transportation. Since skateboards are not allowed on the downtown sidewalks, some skaters opt to use the bike lanes instead.
You can also skate down the Bike Paths, but be cautious, especially at night. Most of them are cracked open due to old age or tree roots.
Ground Zero is the only respectable skateboard store in town. It is the only local shop where you can buy individual parts, maintenance supplies, and custom-made boards. Big 5 Sporting Goods sells some complete boards, but they are almost all of terrible quality. With the exception of some deals found online, one should assume that any new skateboard under $50 is utter trash.
West Coast Crush is a shop in the County Fair Mall (Woodland) that carries Surf, Skate, BMX and other things connected to that life.
There was a Davis Skate Society composed of UC Davis students, but they appear to be mostly dormant these days except for the occasional reunion.
Local pro skaters include Eric Brockman and Nyjah Huston.
Cover of Slap Magazine, January 2008, allegedly in Davis, California. 
This map shows areas of town in which skateboarding is restricted. In the yellow shaded region, skateboarding is not allowed on sidewalks. The red regions represent the roughly approximate locations where no skateboarding is allowed whatsoever.
And for some reason, cops will stop you from skating in the empty Marketplace parking lots at night, claiming that it is illegal to skate anywhere in Davis. He was in an unmarked car too.
According to Section 6.02.050 of the Davis Municipal Code, skateboarding outdoors on most publicly used private properties (such as business parking lots) is, by default, legal. In areas where skateboarding has been deemed unsafe by the city manager, property owners are required to post conspicuous signs stating that skateboarding is prohibited.
Some businesses are not cool with having skateboards upon their premises at all, even if they are being carried continuously, strapped onto backpacks, or tucked away in any other discreet manner. Businesses that are not skateboard-friendly should be listed here.
Grinding damage
Concrete ledge outside the Rec hall. Notice the little metal bars that discourage skateboarders from grinding. 
Concrete ledge outside the Hutchison Hall. Look at how the edge has been worn away and note the paint from the skateboards everywhere.
Art
A bench made from used skateboards located in front of Davis Barber Shop.
