ePortfolios in knowledge networks

Organize a knowledge network using a web tool of your preference, e.g. forum, blog-page, Google-groups, etc. Research a topic related to the learning material which is interesting for the students. Contact partner institutions where students and teachers are also creating ePortfolios, using a detailed concept map. Organize knowledge sharing and get acquainted with the partner's experiences, knowledge and competences through its ePortfolio.
After your knowledge-sharing experience, please post a brief description about benefits, disadvantages, success stories and difficulties.