Hanna Sheckhter over at Edudemic says she has to fool her colleagues at her school (K12, USA) into blogging by calling it Journaling. Any teacher involved with languages will benefit from a blog where her students can read about what she is thinking. She recommends KidBlog, but for language learners in high school (and Jr. Hi) classes worldwide there is PikiFriends. Once security is dealt with, the hard part of setting up an interaction pattern is the next step. Blogging at least once a day sounds onerous, but once you learn how to do it, you can post in very short spurts, or hold your thoughts until the end of the day, depending on how you feel.
Pikifriends makes the interaction easier and simpler with special areas for different kinds of discussion.