Call me a romantic, but I love the idea of Zeppelins! My partner and I had tried to get a ride when we were in Germany a few years ago, but the season was already booked up in Frederickshafen, but now there is a Zeppelin in the US.
An enterprising couple in San Francisco have brought one of the huge airships to the bay area. When the weather is good, they offer sightseeing rides over the city and surrounding area. The trips leave from Moffeft Field and last around 2 hours.
I really can't imagine anything quite as spectacular as floating over the Golden Gate at sunset in the modern descendant of the 1930's airship. More here.