Keep in mind you have a shorter day during the winter. It starts getting dark around 4-5pm. Most of your time visiting Neuschwanstein, Salzburg, Innsbruck or Zurich would be spent on the train. I think taking a train to the borders is a waste of time for a 1 day day trip. Maybe if you spend the night, it might make it worthwile, but that is up to you.

From Stuttgart, we rented a car and visted the Castles of Hohenzollern and Lichtenstein during a December visit. Lichtenstein was totally closed but you can walk the perimeter - the view from the village below looking up the cliff was very impressive. And Hohenzollern was mostly closed expcept for 2 chapels and they had limited hours for touring a section inside which we skipped since we did not want to wait. But the walk up from the parking lot was challenging with our children and fun as well. It is not very easy to drive the rural roads in the dark. There are not that many street lights.

Depending on your interests and comfort with driving maybe drive to Hohenzollern and check out the town of Tübingen along the way. Or just use the public transport from Stuttgart and visit the Mercedes benz museum or the towns of Esslingen and Ludwigsburg which have Christmas markets if you visit before Christmas. There are many things to do near Stuttgart to take up your day.

Austria and Switzerland are really too far for a day trip.

Nice places to see around Stuttgart would first be any of the towns at the ends of the six S-bahn routes. All are pleasant to visit, and you could spend a few hours in almost any of them except I would not visit Plochingen unless you are into modern architecture and the Hundertwasser apartments. Marbach was the birthplace of the poet Schiller, Weil der Stadt of the astronomer Keppler, and Schorndorf of the auto inventor Daimler. All three have museums dedicated to their favorite sons.

As Suburbanite mentioned, Ludwigsburg ( www.ludwigsburg.de ) with its great palace and Esslingen ( www.esslingen.de ) with its well-preserved medieval center are both excellent places to visit, besides their themed Christmas Markets.

There are three well-preserved medieval monasteries I really enjoy not too far from Stuttgart, Bebenhausen (by Tuebingen ( www.tuebingen.de )- excellent town with hilly cobblestone streets and one of Europe's oldest universities), world-heritage Maulbronn (north of Pforzheim), and Comburg (east of Schwaebisch Hall ( www.schwaebischhall.de )- nice town too). The castle (fortress) ruins of Hohenzollern, the largest of the Schwaebisch Alb (low limestone mountains with lots of castles and caves and excellent cliffside scenery- www.schwaebischealb.de ). All of these places are in www.schloesser-und-gaerten.de as are the Ludwigsburg Palace and the Stuttgart palaces. The previously mentioned castles Burg Hohenzollern ( www.burg-hohenzollern.com ) and Schloss Lichtenstein ( www.schloss-lichtenstein.de only in German) are excellent fairytale-like castles.

Germany's oldest state stables, Marbach (Gomadingen) - www.gestuet-marbach.de - can be visited on the Alb for close-up views of the magnificent stallions in their stalls, and by pre-arrangement, you can take a coach or sleigh ride.

The three walled towns of the Romantic Road, Rothenburg ob der Tauber, Dinkelsbuehl, and Noerdlingen, are all within a two hour drive of Stuttgart.

Most of the above places are most easily visited by car. For places that can be easily be visited by train (can use the Baden-Wuerttemberg group day travel train ticket for 27€ for 2-5 people) consider, Ulm with its record height cathedral spire, Baden Baden and Heidelberg. You could also take trains through the Black Forest.

As previously mentioned, it gets dark at 4:30 plus or minus a few minutes through December.

An overnight trip to Neuschwanstein Palace by Fuessen is also possible. If you do this on a weekend, a Schönes Wochende group day train ticket for 2-5 people for I believe 33€ can be used. We always enjoy staying at Villa Jaegerhaus in Hohenschwangau with its close-up views of the lit-up by night palaces. For my review, click on my name, and another reviewer has taken some excellent photos. If you drive, it's easy to drive through the nearby Austrian Alps which will look nice if htere is snow on them. The trip to Ludwig II's palace at Linderhof will accomplish this.

I think that I would skip traveling to Switzerland or Austria for even a two day trip as a lot of time will be lost traveling, and not enough time to see things. And of course, the weather is another factor. No need of traveling there if you can't see the Alps.

Strasbourg, France is much closer than either Switzerland or Austria. They also have a large Christmas market that lasts until New Year's Eve. Strasbourg can be quickly accessed by either car or train. However, I don't know how conveniently if using the Baden Wuerttemberg ticket which has some restrictions: valid only after 9AM on weekdays; and only regional trains (no ICs, ECs, or ICEs). You could possibly use this ticket to Kehl, and then purchase a regular ticket for the short trip across the Rhine. Train information can be found at www.bahn.de , and then change the language to English.