The woman who steps out of the limo at the end of the movie, almost walking into the distracted Pierre, is played by Katja Schuurman. She played Katya in the original 2003 Dutch version of the movie by Theo van Gogh.
When Pierre is looking around the apartment he stops briefly at a photo of a man and a woman. The man is Theo van Gogh - director of the original movie, and the woman is Katja Schuurman, the lead actress in the original.
The main characters are named Pierre (Steve Buscemi) and Katya (Sienna Miller). In the original Dutch movie on which this remake was based, the main characters were also named Pierre and Katja, named after the actors portraying them (Pierre Bokma and Katja Schuurman respectively).
Right after the taxi, where Pierre (Steve Buscemi) is in, hits a van, and the shot moves over to the bus, the name of the moving company is clearly visible. It is named "Van Gogh Movers". Theo van Gogh is the director of the original Dutch version of this movie. Also, the fan asking Katya for an autograph is named Theo.