I don't see any standard mechanism and so I'm not sure how to go about this.  I have a general understanding, but that doesn't answer the question.  I am sure I don't want to intercept all possible uploads; just the uploads from this specific content type.  So, can I define a file upload hook which is scoped to this specific content type?  I haven't seen anything that makes me believe I can.  Can I create a custom file field to use any time I need to perform a conversion?  Can my custom file field "extend" the existing file field, so I don't have to port improvements/bugfixes to my custom file field version?

So many questions...  (-:

Thanks for the help,

Chris.