Capture of DDL Statement

I want to be able to capture in a database trigger all of the changes made to the database schemas by any and all users. As a part of that, I can get the user_id, the object name, object type, and schema with no problem via sys.dictionary_obj...

I am running both Oracle9i and Oracle8i Enterprise (on separate machines).

Does anyone have any ideas on how to capture the actual ddl statement (either before or after it is sent to the database)?

PS - I've looked in all of the manuals that I have, so, if you are going to send me back to the manuals for further reference checking, please point me to the appropriate manual to look at. Thanks.