Luis let me know that The Street teamed up with Polar Mobile to create a free BlackBerry application. It allows you to access certain parts of The Street from your BlackBerry. I am not sure how well it works but it looks purty.
I am not sure why you would not just use a multipurpose RSS reader but the articles do format quite well on in the reader. It does not look like you can add your own RSS feeds so this app is a one trick horse.