Along the same lines as penpals, a Postcard Exchange can work wonders for students learning geography. When a postcard comes in from another state or country, have your students find that spot on the map. Discuss that country' s culture, foods they like to eat and sports they like to play. Talk about the similarities and differences in that country then the country that the students live in. There are many forums that are regulated and watched over to prevent swearing and topics that don't need to be seen by young eyes.
Forums are a great way to exchange views and ideas.
This could also be a great way to work in journal entries. Set up a forum that only your classroom has access to, then propose a topic. Your students will be posting their responses to both the topic and commenting on how the other students think. As you can see, there are many ways to make learning about the world fun and exciting. Since children are naturally curious, all you need to do is provide the opportunities.