A.k.a. "Oh-my-god-this-is-so-awesome-why-did-no-one-ever-think-of-it-before"
Lang-8 is a blogging website where you post entries in a language you wanna learn. From there, native speakers correct it so it sounds more natural.
Of course, they're learning a language too, so you can correct their entries too.
It's a really neat way to gain better language, and you can make friends along the way!