The mobile computing represents a new possibility for the people "learning while doing" their everyday activities. The advent of mobile devices has created new opportunities that go beyond the simple communication; their software interfaces have a primary role in enabling the communication and collaboration among the evolved parties. In a learning environment for informal education, it is essential to design interfaces that minimize the interaction difficulties and maximize the learning activities itself. To achieve this, in this work is presented a design proposal and prototype of a mobile phone interface for mobile collaborative discussion. The proposal combines mobile learning with collaborative learning, stimulating the constitution of communities of practice aiming to promote the informal education. © 2009 Springer Berlin Heidelberg.5621 LNCS 515524Naismith, L., Lonsdale, P., Vavoula, G., Sharples, M., Report 11: Literature review in mobile technologies and learning (2006) Future Lab, , http://www.futurelab.org.uk/resources/documents/lit-reviews/ Mobile-Review.pdf, University of BirminghamSmith, M.K., Introducing informal education: What is informal education? Where does it happen? (1997) How Has It Developed, , http://www.infed.org/i-intro.htm#whatFino, C.A., (2004) What Is Collaborative Learning, , http://www.uma.pt/carlosfino/Documentos/PowerPoint-Aprendizagem- colaborativa.pdfDutra, R.L.S., (2002) Learning Environment for the Teaching of Computer Networks Oriented to Problems, , Institute of Informatics, Master Dissertation. Federal University of Rio Grande do Sul, Porto Alegre, BrazilNitzke, J., Carneiro, M.L.F., Geller, M., Creation of environments for collaborative learning (1999) X Brazilian Symposium of Informatic in Education, , Curitiba/PRTrifonova, A., Mobile learning: Review of the literature (2003) Technical Report, , University of Trento. Department of Information and Communication TechnologyNicolini, D., Gherardi, S., Yanow, D., (2003) Knowing in Organizations: A Practice-Based Approach, , M. E. SharpeWenger, E., (1999) Communities of Practice: Learning Meaning and Identity, , Cambridge University Press CambridgeWenger, E., Communities of practice: Learning as a social system (1998) Systems Thinker, , http://www.co-i-l.com/coil/knowledge-garden/cop/lss.shtmlBentley, T., (1998) Learning beyond the Classroom: Education for A Changing World, , Routledge, LondonFisher, T., Higgings, C., Loveless, A., Teachers learning with digital technologies: A review of research and projects (2006) Future Labs Series, , http://www.futurelab.org.uk/research/lit-reviews.htmJeffs, T., Smith, M.K., Informal Education: Conversation, democracy and learning (1996) Bramcote Hills, , 3rd edn., Educational Heretics Press, Nottingham