Ligerator makes it easy to use nice OpenType (or otherwise) ligatures in your documents.
What is the Ligerator?
The Ligerator generates a Microsoft Word (Visual Basic) macro which does all the heavy-lifting for replacing a bunch of letters across a number of styles. If you're typographically inclined, it means you can easily convert this:
into this:
... without tedium.
How do I use it?
Instructions are available for:
Essentially, you generate a macro with Ligerator, add it to your document or master template. Once added, you can run it when ever you need. Because the source of the macro is generated, you can get in there and tinker if you want too.
Who is it for?
Ligerator is for anyone who cares about typography, and is frustrated that in the year 2007, Microsoft still hasn't added automatic ligatures for Office 2007. That said, the macro should work for older versions of Word (2003 etc), and presumably also for the Mac version.
It should also be noted that Ligerator is for people who have an intermediate level of skill - it's not going to magically transform your document at a push of a button.
Is it safe?
Pretty much. I advise you only ever run Ligerator on a copy of a document. Run it at the end of the document finishing process, as close as possible to printing or PDFing. Once Ligerated, the document likely (depending on what you've Ligerated) fail spell checking and so forth.
So to repeat, run Ligerator at the end, and on a separate copy.
I developed Ligerator to help format my thesis (200+ pages), so it works on large documents reliably.