Working in groups, students create blogs (using blogger or another free, easy-to-use tool) which present themselves and aspects of their local culture. Students from the different partner universities then post comments and questions on their partners' blogs.
You can see previous examples of blogs which my students made for an exchange here: http://killingtorrente.blogspot.com.es/ http://places-of-wonder.blogspot.com.es/ http://ourrealspain.blogspot.com.es/
Usually, students create the blogs in their target language and receive feedback from their partners in this same language. This would mean that in a Spanish-American exchange, the Spanish students would create their blogs in English and the Americans would create their blogs in Spanish.