I've tried this activity in almost all the first day of classes I've had, and it helps to set a light tone for the class. Instead of introducing everyone individually, this activity is more communicative. I pair students up into groups of 3 or 4, and I typically ask them to find 3 things they have in common without mentioning a few things, e.g. country of origin, language, cultural aspects. This forces them to ask questions to each other and find shared things. I think finding things that students have in common also helps to bring different cultures together, and provides a friendlier learning environment. After they finish their list, I ask each person to share one thing that they found in common with all their group members.