Transaction logging/Audit trails

Has anyone figured out how to combine these 2 functions? I would like to have a log of who changed which tables, when they did it,and the before and after data. It seems like all of this must be going into the transaction log, and that it would save a whole lot of time if I could derive it from there rather than setting up triggers or application code (heaven forbid) to write audit transactions. I know someone out there must have resolved this. If not, there are probably a whole lot of MIS shops that would pay for this type of utility for those of you entrepeneurally inclined.