Microsoft SharePoint is the collaboration platform of choice for many businesses, providing a portal for file sharing, communication, and content management. The SharePlus Office Mobile Client (iPhone, $14.99) lets you connect to your SharePoint installation from the road and sync the SharePoint lists and libraries you need. You can share calendars and task lists with your team, as well as edit documents, participate in discussions, and contribute to wiki pages. The software stores accessed data on the phone, so you can work with it offline and then sync it back next time you connect. It works with existing SharePoint credentials and doesn't require any new server-side components.