Check out the PocketGenie wireless portal; I think you go to http://www.pocketgenie.com from the desktop to get setup. Last time I checked it was free.
HillCast's MidCast Pro can stream real-time stock quotes to the Blackberry. Your BB 6750 must be hosted on a BES and have MDS enabled. You can download a free demo by going to www.hillcast.com and click on "Take a Trial".