Sorry if this is a multiple post, but I tried responding once and it didn't post. I never did follow up further on this single-audit-table approach to auditing, since it is of somewhat limited use (reconstructing data using this mechanism would be pretty complex). I did write another article series on this site, however, entitled "Writing Nearly Codeless Apps", which discusses a much more practical and comprehensive auditing mechnism that allows you to easily recall every row of every table of an application as of a given date.