Today I stumbled upon a couple of good articles about jazz improvisation, ear training, and transcribing at pianologist.com. I especially enjoyed their Essense of Jazz article. In the article, they explain the importance of ear training in jazz improvisation, and also touch upon the difference between being able to play the ideas in your head and simply using theory to run through changes. I've discussed these concepts quite a bit on this site, so it's great to see that others are similarly getting the word out. They've also done a nice job of including video clips to reinforce key points.