What is Service Application Framework?
Populating name of files from SharePoint Document library in a drop down list
Introduction of SPPersistedObject class
Thanks, I've created a sample service application built on top of the SharePoint 2010 Shared Service Architecure as starting point for custom development: http://www.parago.de/2011/09/paragoservices-a-sharepoint-2010-service-application-sample/