(Open-Air Celebration) It's the public celebration of the construction of SAM's Olympic Sculpture Park. There will be music, raffles, dancing, drinks, and valet bike parking. It's also a chance to catch BeresCullerSutton's brilliant Trailer Park and performances by Fankick! and jump-rope wizards On the Double (Dutch). (Olympic Sculpture Park site, Broad St and Elliott Ave, 654-3200. 4:30–8:30 pm, free.) NATE LIPPENS