I saw it at an annual summer party on Saturday, too in upper western Washington State, here stateside. With the Moon and the meteor shower, I felt like it was a extra special treat. Even if I hadn't known where to look, I would have known it was the ISS. Brightest artificial satellite in the sky.
Led to an interesting argument with me occupying the position that any kind of space projects IS NOT A TOTAL WASTE of money, and having to explain just how small NASA's budget is.