A few other questions, as someone mentioned this isn't the ideal and I have to put auditing into our applications sometime soon!

When designing from scratch is the auditing best done as part of the calling stored procedure or is it best in the calling application?

Assuming the database structure is large and complex would the data still be pivoted or replicate the table structure (perhaps in a separate database/server) or storing versions in the same table?

How important is user friendliness when viewing of the audit trail (does anyone have any experience of end users wanting to view a record of changes without tech support)?

What additional functionality would you expect to provide such as archiving etc.