Drag&Drop between different Database has been asked for in a lot of our Projects.
For example a Mailtemplate with an extra frame which holds some sort of TeamMailbox. You can simply drag and drop Mails you got into the frame to make them available for the whole team.
Of Course it's possible to use CTRL+C / CTRL+V or a button with some Lotusscript code. But Users are use to Drag&Drop anything they want between any program they have.