Auditing XP event security logs

[Gary Collis <onesl1fox () 27 eclipse co uk>]

Hi List,

I am aiming to monitor the useage of local admin accounts that I have 
set up on 40 machines. I have turned on auditng for the machines via 
group policy, and events seem to be logging OK. However I would like to 
automatically consolidate the logs into one central location, possibly 
an SQL database for ease of reference and historical purposes, and if 
possible produce some stats from them ( in a graph if possible, for 
management) e.g amount of times logged in on a particular day/week etc.

Does anyone know of any tools that can help me achieve this? Ideally I 
am looking for free tools.

Thanks,