I have been leveraging the CiviCase component of CiviCRM to help a crisis response organization transition to a paperless process. I was originally tasked with "fixing" a Microsoft implementation of a custom web application written in VBScript and MS SQL Server but after fighting with the former developers horrible code I finally decided to migrate the system over to an open source LAMP implementation leveraging J! 1.5 and CiviCRM 3.1.