Hey, a few weeks ago I read this article by Al Mohler, and it really hit me that I'd never thought before about the difference between original sin and total depravity. I highly recommend the article, and ask for your thoughts. 
http://www.sbts.edu/mohler/FidelitasRead.php?article=fidel036
http://www.sbts.edu/mohler/FidelitasRead.php?article=fidel036