DocsFlow unites the collaborative editing power of Google Docs to the layout power of InDesign.
DocsFlow lets you place online Google Docs documents as InDesign story contents, just like normal text files. More importantly, DocsFlow maintains a dynamic link so it can intelligently merge Google Docs document changes into the InDesign story contents on each link update, rather than just replacing the story. So you can format, layout, and make minor edits in InDesign, while you and others edit story content together in real time on Google Docs, without losing any work.
DocsFlow Pro, required to import Google spreadsheets and to use the export functions, is $400 US. More information is available on the developer's Web site.