WiZiQ is a place where you can teach and learn using an easy-to-use Virtual Classroom. You are welcome to give private and public live online sessions, teach for free or earn money teaching. As a learner you can attend public sessions on various topics from academics to anything under the sun.
The Mixxer is a free educational community for language learners and teachers to find a language partner for a language exchange. The language partner is someone who speaks the language you study as their native language and is studying your native language. As a member of the Mixxer community, you can communicate with your language partner via Skype to practice speaking. You can also submit documents and ask native speakers to correct your writing.