If you are editing a large document (as I have been) you may find this of use in collecting your acronyms....
AcroWizard 2.0 from Anvil Logic.
It tries to identify associated text as the definition of the acronym from the document and provides links to lookup on the Web to help you fill in the blanks. It creates a database as you go and generates a Word table for you. I found it pretty useful - I was able to compile a table of 255 unique acronyms (many of them appeared multiple times) from a 1100 page set of documents in a couple of hours.