I’m not the worlds biggest BB fan, but looking at the large installed base of both BlackBerry and SharePoint this maybe a solution to look into.
"BerryPoint Connect mobilizes SharePoint Services by breaking down its complex web interface into smaller sections appropriate for display on a BlackBerry browser. Without BerryPoint Connect, BlackBerry users trying to access SharePoint will be frustrated by web pages that are nearly impossible to read, javascript errors, and pages that are too large to load. BerryPoint Connect enables mobile users to read, edit and create items in all SharePoint lists: tasks, issues, announcements, links, contacts, discussions, events, document libraries, and custom lists. This includes access to custom columns and views. BerryPoint Connect provides access to SharePoint Portal Server areas, news items, and all SharePoint lists belonging to Portal areas. BerryPoint Connect enables the modification of SharePoint alerts to direct BlackBerry users to the appropriate site menu. BerryPoint Connect provides a framework for the display of third-party Web Parts. "
[Via MS Exchange Blog ]