SharePoint and Spreadsheets

Project managers and administrators often keep spreadsheets tucked away on their desktops and devices. At a minimum, we want these files secured inside SharePoint.  Users can log in through their browser, open and edit in the cloud, without having the files touch any local drive. Users can also determine whether or not to share the files.  Going a bit further, it is easy enough in many circumstances to use the tools built into SharePoint for managing the same information, without the need for any spreadsheets.