The catch is...you gotta be a blackberry user!!!
I found a cool tool in the Blackberry application store. It's called "Homes for Sale by Smarter Agent". You can search listings and homes for sale by Broker/zipcode...basically like MLS. First you have to have a blackberry (LOL), then you download Blackberry Application World to your phone, go to:
Follow the directions to download and install. Once you have done so, go ahead into the icon/app on your phone and go to the search option and type in "Homes For Sale"...it will take you right to the application and give you step by step insturctions to download and install.
I am sure there may be something similar for those who use Iphones (they have meebo for Iphone and not blackberry...darnit!!!) but this is of course for those of us who are loyal to good old blackberry!!