Of course you should go and visit the Boeing plant, the largest single plant built by mankind. It is quite amazing to see the airplanes being assembled in front of your eyes and see the planes test flying over your head. Microsoft headquater is in Seattle too, just in case you are not too fed up with them. There is also a fishman's market in Seattle which is quite famous, worth a visit. (next to downtown). You can also take the ferries and visit some of the islands in the bay area. Sea water is cold and dark blue and calm, very sensational cold salt water. Their aquarium is somewhat interesting. It is built under sea water and you sit on the sea floor and see the fishes in their natural habitat. Seattle is a nice and quitet place maybe worth 2-3 days of your time. Enjoy.