Mozartkugeln (translation = mozart balls) is everywhere! The chocolate pralien filled balls are a very popular souvenir and treat for friends back home. However, you may want to try one before you buy many. I am not that fond of them and if you're looking for chocolate, I'd highly recommend Milka bars instead. They have some amazing varietys of Milka including a smores ripoff that hits home for the Americans.
If you're American, be careful in a restaurant. Soda is not bottomless, and when they place a basket of bread on your table, it's not free. They charge you by the slice, so watch out. Also, what you see on the menu is what you get. No rolls, side salads, or steamed veggies. This can get pricey when you have to order several different items.
In all the shops you'll see they sell some Mozart's chocolates. Don't try them, it will be your ruin. They're so delicious that you will want to buy all of them!!!
Well... try them!