Every year, Orange sponsors an outdoor theater in Bern, Geneva, Zurich, and (next year) Basel. It's fabulous- a great outdoor setting with restaurants and clean bathrooms (how Swiss!).
Tickets go on sale June 30. Check out the website and be prepared, tickets go fast!
Last year I bought our tickets to Wanted and Son of Rambow online without any problems; unless you count sitting Marion in front of the TV for a half hour so I could buy tickets before they sold out a problem. I don't.
After you have your tickets and you've waited anxiously for your night at the movies to arrive, get there early! Seats get reserved fast.
In summary: Tickets go fast. Seats go fast. Proof that this is a great way to get out in the summer. So go already!