We (furfly) have been using Nettracker for a couple of years now.
It's not open source but it's spiffy enough that I'm willing to
overlook that. :)
We've never had any trouble with it reading AOLserver access
logs. You can tell Nettracker where to look for log files (via an
absolute path) so as long as they are on the same system and
the user running Nettracker has permission to read them, you
don't need to copy them anywhere.
