This is a garage sale gone wild, except that everything is FREE! If you have extra crap, or need more, this is the event for you. You can just unload it and leave - there's no setting up a table to hock your wares.
Last year, I got a beautiful, solid wood, hand-painted room divider, a nice chest of drawers, Mom got a really ugly chair that she loves (which is probably going BACK to the S&S this year), and I can't remember what Lou got. Tools? Not sure. I know that we had to make two trips in the Land Rover (RIP Salty Bob) because we snatched too much stuff.
If you want to know more about it, here's a link to the City of Renton's webpage on the S&S. Ignore the date - it was for last year, but I just confirmed the date for this year over the phone with the coordinator.
Have fun, reuse, and recycle!