2. QT Sydney -- Sydney, Australia
If you looked up "state-of-the-art intuitive interaction" in a dictionary of really long words/ phrases that sound impressive, you'd see a picture of the elevator at QT Sydney. It senses how many people are in it, then plays music based on the number of passengers. One passenger'll yield something slow (maybe Adele?). A big group enters, however, and suddenly it's party time with Katy Perry -- whether you'll actually start dancing in a box full of strangers is another question entirely.