>None. But you can create one then call it on the INSERT/UPDATE Triggers. You need to have a field ofcourse for stamping. Even the deleted status is considered a field but a hidden one.
Jess,
You cannot use the INSERT and UPDATE triggers to record a datetime stamp on a record. It will cause an error if you try to change anything on the table that the trigger is firing for from within the trigger. You can do it from the record level validation rule though.
You really shouldn't recommend things you haven't done yourself because you ahve no body of knowledge to know if it works or not. You shoudl at least qualify your recommendation by saying you have not done it yourself and you may be incorrect.