This chapter describes the teaching approach called problem-based learning (PBL) and discusses the creative ways it was used to carry out successful activities in virtual classrooms on Japan’s island in Second Life (SL). Problem-based learning provides students with challenging, ill-structured problems related to their daily lives. The students receive guidance from their teachers and work cooperatively in a group where they hold brainstorming sessions to seek solutions to the problems. The authors are researchers who successfully carried out PBL activities with students in SL. This chapter presents and describes some of their activities in detail. For one example, students are asked to design and build the house of the future during the global warming era. In another one, students are asked to design and build the eco car of the future. An eco car is energy efficient, safe, and environmentally friendly. In a third activity about nuclear safety, students are asked to find out what kind of metals can effectively protect human beings from radiation. For an activity about renewable energy, the students decided to build a special airplane for wind energy. The final activity is about a virtual workshop for elementary school teachers (teachers of young children). The workshop provided them with creative teaching techniques to engage and turn students on to learning. The teachers were asked to select one of the creative teaching methods and use it to prepare a creative activity for their students and to share it with the SL workshop participants.