Tandem Language Learning is a system of learning to speak a foreign language whereby you meet up with a native speaker of that language and converse. For example, your fluency in Spanish might help out a Chinese person who wants to learn Spanish, and during meetings they will also teach you Chinese.
It's great fun, informal, and free. Most universities in the UK run a scheme where you can meet a partner online. You are matched according to the languages you speak and want to learn, how well you speak, and other interests. My Tandem partner is from Germany and is a great help in preparing me for moving to Austria next year. She's also fast becoming one of my best friends - it's a great thing to do if you've moved to a new city and want to meet people. We have so much in common (although we usually talk about musical theatre and South-East Asian literature in English; her English is embarrassingly superior to my German) and we hang out all the time.
I'd recommend the scheme to anyone who wants to improve their language skills. It's free, and has helped my vocabulary and confidence so much. Not so sure about the other way round though - her English is near-perfect. Today we talked about laser eye surgery. The only piece of vocabulary she asked for was "astigmatism". Incidentally, in German, that's "der Astigmatismus".