There's the long weekend in Mid May'15, and a friend coming for a visit. I have planned Zurich, Luzern, and thrown in Rigi too. But with the weather being quite unpredictable, I wonder if city walking, or going uphill, would be a good idea in the rain. And what could be the alternatives, i.e. where to bring visitors on a rainy day in Switzerland?
Zoologisches Museum and Landesmuseum-absolutely! Kunsthaus as well, of course. Also, consider things like Laser Tag, Escape Room Zurich, the Hurliman Spa, etc.
If the rain is not heavy, going to the Zoo up in Fluntern is a good option. There are less people there and the experience is almost the same (again if the rain is not heavy). Plus several of the things you see are indoors.
Well if the few museums are off the cards, you could just do bars, pubs, cafes and restaurants, failing that, sit at home with a Jigsaw puzzle, deck of cards, cup of tea, DVD!
If they are into doing something, you could try Ice Skating at an indoor rink, a pool hall, one of the Casinos, Go Karting.
Take the train south to Ticino... Its always sunnier down there
I'd say that's a pretty "Swiss" activity... and neat history. The drive is nice and towns are cute...I really liked the Absinthe house, which is a small (but well done) museum where you can sit and watch a video about the crazy history of the drink (and video clips from former bootleggers) and do a tasting...