I found this very interesting comment on Dave Hartline's blog. This simple analogy beats most apologetic arguments I have read regarding sola scriptura!
"Another thing I have never been able to understand about the Protestant line of thought is, why IS it OK for me to interpret the Bible however I want, so long as it is not Catholic teaching? I can be an authority, but not the Church. It's like in Shakespeare class, I was always glad when the instructor explained things to us, because, well, she had years of study, and I didn't, and she knew background that I didn't. If she would have said: "You are on your own. It is 'Shakespeare alone', " I probably would have flunked the class. "
Yes my friends, using Sola Shakespeara may cause you to flunk the class!