Found an interesting reading resource via this blog post:
http://nihongoup.com/blog/reading-material-aesops-fables/
The blog itself has some other interesting posts that you might want to check out:
If you go to the top page at the URL, it looks like they have developed some kind of CALL (computer aided language learning) application for Japanese. There's a free version, and the full version is about $5. Don't have time to try the free version just now, but if anyone does, let us know what you think!

