InDesign's Find Font and/or Find/Change (set to Search: Document) commands are the fastest way to change text formatting throughout a document. Both automatically search and replace in Master pages as well as document pages, and both can find text formatted with a missing font and change its typeface to one available.
Tiplet: Bet you didn't know that Find/Change's Find Format Settings, revealed by clicking More Options in Edit -> Find/Change, could find missing fonts, did you? If missing fonts are called for in the document, their names appear in brackets at the very end of the dropdown menu of typefaces in the Basic Character Formats panel. If you don't see yours, try choosing any font from this menu, click in another field, then go back to the dropdown menu and look at the bottom ones again. It's like a mini-Refresh … your missing fonts should now appear.
Find Font and Find/Change Format are also great for changing all usage of a Type 1 or TrueType typeface to an Open Type version. A lot of clients moving to InDesign/InCopy workflows are doing this to their publication templates to make cross-platform work easier. (The same Open Type font can be used as is on both Mac OS X and Windows 2000/XP.) And many other places are moving to Open Type to take advantage of OT-only features:
http://www.senecadesign.com/designgeek/opentype.html more >
Adobe InCopy CS users are able to open InDesign files and edit copy in text frames. They can choose to view the text they're editing in either Layout View (same as InDesign), Story View (same as InDesign's Edit -> Edit in Story Editor), or Galley View (just like Story View but it shows accurate line endings).
Since many editors using InCopy are recovering from Microsoft Word, they often prefer to work in Galley or Story view, as it it's most similar to Word's "Normal" view. And of course, these views are a lot easier on the eyes when you're doing heavy text editing, because the editor gets to choose which typeface all text in Galley/View is displayed in. (Just as how InDesign users can choose which typeface to use in the Story Editor via Preferences -> Story Editor Display.)
When I'm helping new InDesign users understand exactly what "flattening transparency" means, I like to show them a concrete example. One way is to export the same simple InDesign file (containing a few overlapping transparent objects) to PDF twice: Once as an Acrobat 4-compatible (PDF 1.3) PDF, which flattens transparent objects, often splitting them up into "atomic regions;" and again as an Acrobat 5-compatible (PDF 1.4) PDF, which supports transparency and thus doesn't flatten.more >