Over the last couple of years they have popped up all over Europe - and now have made their way to Zurich too: the so-called free walking tours. In Zurich they offer daily guided walks through the old town, mostly in English (usually at 11:00, meeting point is Paradeplatz), on some days in Spanish too. The old-town tour features all the classic sights and some history. They also have other tours like the Zurich West tour to the former industrial district and a Langstrasse tour. Tours last around 90 minutes and are a nice way to get a first feel of the city. Note that while these tours are technically free, you really are expected to tip at the end (the website says 11Sfr). Check their website for available tours and meeting points, no need to book.