Here are a few photos of Mercurial Sky, the art installation / lightshow at downtown Portland's Director Park . This is by Seattle artist Dan Corson, who also created the Nepenthes (which are illuminated as well) along NW Davis in Old Town. Portland doesn't have a lot of public art that needs to be seen at night. Other than the two Corson pieces, there's More Everyday Sunshine along the NS streetcar line, and the untitled neon piece on the parking garage at NW 1st & Davis. There might be others, but these are the only ones I can think of off the top of my head.
Anyway, the RACC page for Mercurial Sky describes the concept behind it in more detail. The digital video aspect wasn't obvious to me as I was watching it, but it's possible I was being impatient and didn't stay long enough. This might be a fun place to sneak in the occasional Rick Astley video without most viewers noticing.
Mercurial Sky is an ever-changing array of light played on LED tubes integrated into the Director Park Canopy. The digital video only emits from the lighted bars, and provides a sense of movement through an abstract tapestry of light and color. If you stand farther away, or look in nearby reflections, the images are compressed and give a clearer view of the video.
“...it seemed like a natural idea to infuse the randomness of the movement of nature into [this hardscaped park]... The inspiration for the images came from my own personal interests and exploration in natural patterns of movement. You can see the natural elements of water, fire, and air expressed in the video. You can also catch movements from creatures under a microscope and worms crawling across fresh moss, jellyfish pulsating, birds flying, and strings of kelp swaying in the ocean current.”