Adding Vocab Lists/Interests
I'm a pretty new user at this awesome site, but I have a suggestion (though I don't know if it makes sense).
I've see many people complain about the vocabulary on the lesson portion of Duolingo. I was thinking that we have an option to upload vocab lists, or have vocab interests. For example, if I was interested in cartoons, I would click the cartoon (or arts) list, and it would put in words like dibujo, or historieta. Also, maybe having users create their own vocab lists.
(A problem I foresee is that this site is meant to translate documents, and need general vocabulary).
I think this would work just fine if you uploaded documents for translation that related to cartoons. Then you could pick which words (or Duolingo could pick) which words to include in your practice. I too could see this getting out of control though. A million users uploading their own words could get a little crazy in the back office.