Mobile technologies like mobile phones allow a learning community to combine classroom activities with simultaneous field explorations in an authentic environment. The collaboration between the two groups can be enhanced by a technique called Collaborative Concept Maps, based on SMSs (Short Message Service). This means that mobile technology is used not just as a mediator (of learning activity/collaboration) but as a trigger and platform that includes guidance and support for learning methods and the learning process. A formative evaluation indicates that it is possible to construct collaborative concept maps by mobile phones (using SMSs) and combine simultaneous classroom learning activity with mobile learning. In the conducted case study, the students in the forest sent their observations, represented as concept maps, as structured SMSs to the students in the classroom. Our experience shows that even light and easy techniques can make a difference in a learning setting, if they are carefully designed to fit the real users' context.