The Apple downloads page for Mac OS X productivity tools at http://www.apple.com/downloads/macosx/productivity_tools/pagezephyr.html includes PageZephyr Search. This one of Markzware‘s productivity tools is a content search application that can find specific content in InDesign files.
Desktop search engine, PageZephyr Search, is ideal for print publishing or digital publishing (including online books, magazines, newspapers, etc.). PageZephyr Search can search InDesign file (INDD document) archives to find all documents containing your keywords. This Mac app allows you to search your entire drive in Adobe InDesign desktop publishing (DTP) documents, WITHOUT the InDesign application. You can copy and paste the found text to create new content for print or the internet:
Apple – Downloads – Productivity Tools – PageZephyr