Dear Duolingo staff,
Have you considered compiling the audio from each lesson into an mp3 album or, better still perhaps, an audiobook (which has the advantage of memorizing the point at which you stopped listening)?
I've been doing some audio language lessons over the past few months and I find it a great way to assimilate stuff by listening to the explained lesson and, more importantly, keep from forgetting it, by listening to the lesson review, which comprises each sentence said in English first, then a pause for me to say it in the target language, and then a native speaker saying it himself, so I can check if I got it right. Another advantage of this method is allowing me to multitask, and always finding time each day to review something.
Duolingo is great, and I think it's important to know (and it helps the learning process) how to write, but this might be a nice extra, especially for people pressed for time that want to review what they've learned.
I presume implementing this would be fairly simple...? There could be perhaps one for lessons and another one just for vocabulary.
Fellow Duolinguists, what do your think?