Aug 17, 2010 - 11:46 AM
I have found September to be the best time to visit the area, weather-wise, so good choice!
If you are interested in outdoor activities (such as hiking, anywhere from light to challenging) you may want to consider staying in one of the car-less villages above Interlaken such as Wengen or Murren (Wengen is my personal favorite). Interlaken is rather busy and touristy whereas the mountain villages give you more of the "Swiss" feel. The advantage that Interlaken has is that there is more shopping and nightlife, so this is a consideration as well. You will pass through Wengen on your way up to the Jungfraujoch (I recommend going up this way rather than going up through Grindelwald) and will pass by Murren on the way up to the Schilthorn. If you do stay in one of the villages you can easily return to Interlaken Ost to catch the ferry to Brienz then train on to Meiringen.
There is nearly a limitless number of things to do in the region. I have a 30+ page document of transport tips, excursions, and so on that I'd be happy to send you but need your email address to do so. If you are interested, send it to me via private message feature, don't post your address up on the public forum.
I have never had any problem with using credit cards in Switzerland. However, with all the fraud these days, many credit card companies are now beginning to block international transactions so you need to call before you leave to let them know where you are going. Same with your bank ATM card (which is the most cost-effective way to get cash in Switzerland).
I would recommend the Swiss Card (182 CHF) for your travel discount pass. It will get you a free ticket from Zurich to Interlaken (or wherever your final destination is) and from there back to Geneva plus 50% off of all other travel (boats, buses, trains, lifts) including the expensive Jungfraujoch ticket. However, I think the swiss Card requires you to take the most direct route to your destination. If you decide to take a longer route (which Lucerne would be) suggest you buy the Half Fare Card (99 CHF) instead. 50% off of everything, just no free round trip. It usually works out to be about the same deal as the Swiss Card anyway so perhaps you can just go with this and leave all your options open.