1) I would be real careful how I handle text files that visitors upload.
2) Just recently I read about the music industry starting an all out attack on websites that post guitar tabs and scores of music to which they own the rights. If your visitors upload copyrighted songs that you then publicize, you can probably be held liable. I am not a lawyer so this may not hold water, but if I were you, I would inform myself thoroughly before investing too much in this project.
Here is a related article:
http://news.bbc.co.uk/2/hi/entertainment/4508158.stm