CAROLING: Bring your "instruments, out of tune voices, ugly sweaters, and garbage pickin hobos" for some high-spirited caroling at the 2nd Annual Cacophony Christmas. "Wear your ugly christmas sweaters, old Haloween costumes, or just your naked ass self!"

7:30 p.m. // City Hall "Tree Park" (Polk and McAllister) // free

PARTY: Get some cool locally-made gifts at Indie-Mart NightLife, a Holiday DIY & designer show extravaganza, while enjoying live music by AB and the Sea and Boy in the Bubble. Life/Style DJs Ts and Roll will provide music on the main floor.

6 to 10 p.m. // California Academy of Sciences (55 Music Concourse Dr, Golden Gate Park) // $10-12

ART: The San Francisco Arts Commission celebrates the launch of The ARTery Project, featuring three site-specific light installations by artists Jim Campbell, Theodore Watson and Paul Notzold and art openings at the luggage store, Central City Hospitality House Community Arts Pro"gram, and Gray Area Foundation for the Arts. Tonight's festivities include live music and a community procession to each light installation.

5 to 7 p.m. // 1119 Market Street (across the street from U.N. Plaza) // free