Cisco IOS Software Configuration Management

Here's a great way to archive your IOS configurations and have the option to roll back.  This also creates a detailed configuration change log.

archive 
path disk0:archived-config 
maximum 14 
time-period 1440 
write-memory

Source:  http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080120f48.shtml#ios