Mobility can affect a learner's participation in different communities that support language learning. In this paper we report on our experience with supporting a course in which language students are encouraged to travel to a country where the target language is spoken. On the one hand, students who travel abroad get in contact with local communities,which can promote their learning of the language and the culture. On the other hand, they risk losing contact with their classmates and the support that they provide. In this context we introduced a mobile community blog with the aim of extending the learning arena and promoting the sharing of knowledge among the students, independently of their location. This paper discusses the design considerations for the blog and describes its use to support students' sense of community. An evaluation and analysis of the usage of the blog is presented. These results suggest that the learners lack an identity within the community of language learners and there was no sense of community among the members. Reflecting on these results, we suggest that while a blog might be an appropriate tool for promoting knowledge sharing, it lacks functionalities to promote connectedness among learners and foster their identity as a community.