I've been a couple of times on business, and I think they only widely accept Swiss Francs, but Mags or swissrob can confirm, as they live there.
You need a special 3 prong plug adapter - the usual Euro one doesn't fit. I'll find a picture of one in a bit, but I think swissrob said he could get some for a fiver or something??
Some places do, but most don't. You'll get a much better exchange rate by taking your own Swiss Francs.
Normal UK 2-pin shaver plugs are too big. Euro 2-pin plugs will fit providing the socket is flat. Rebated sockets are getting more common here and for those you'll need a Swiss adapter.
Note that Swiss sockets are 3-pin, to include an Earth if required and are rated to 10A.