We went to Salzburg in 2005 for 5 days. It is very beautiful. We stayed across from Mirabel Gardens which is wonderful to walk through. The museum of Mozart (not his birth house) was informative. Definitely worth going to the Sacher Hotel for some desserts. If you want something a bit different, you can go to the Red Bull Hangar 7. Formula 1 cars and aircraft on display and a super-cool bar above the futuristic glass hangars.