This website has activities for learning English, Spanish, French, German and Italian. All the lessons are kid-friendly with lots of interactive activities and diagrams to learn vocabulary.
This is an online collection of classrooms from around the world that you can become a virtual pen-pal. You can choose any country or language. This is a way for kids to practice language skills with other kids their age.
Adult foreign language resources and a few Twitter feeds can be found in another On The Web blog post here: Learn a Language for Free