When it comes to smart phones, there are currently two forces to be reckoned with: BlackBerry and Windows Mobile. Yes, Palm-based Treos are easy to use, but the OS is ancient and in desperate need of a refresh. And Symbian-based smart phones are virtually non-existent in the U.S.-at least ones you can afford. That leaves RIM's e-mail-centric juggernaut, which has been spruced up in the multimedia department, and Microsoft's nearly ubiquitous platform, the latest version of which sports some nice enhancements across the board.
 
We know you don't shop for a smart phone based on the operating system. The carrier, design, price, and other factors take priority. But the OS is a big deal, as it affects everything from how easy the device is to use and how well it surfs the Web to overall performance and how many good third-party apps you can add to get more out of your investment. Because only one OS can be called the champ, we put both BlackBerry and Windows Mobile 6 through six grueling rounds. Let's get ready to rumble!