The Web Way to Learn a Language
nytimes.com
nytimes.com
This isn't a perfect approach (it's heavily biased towards people who like learning by memorising phrases, rather than people who like learning by picking apart sentences through detailed study of grammar --- I don't think crowdsourcing explanations of grammatical points will ever bring satisfactory results, anyway), but it works well for people who like it.
I really enjoyed this bit?
I looked at Rosetta Stone a year or two ago, and the best they had was occasionally bringing you back to a previous lesson.
It suddenly became clear to me why the waitress across the road would smirk every time I said good night to her, oops.