[Trogdor]

Since FC3 Fedora and RHEL come with a version of vixie cron that generates messages in your messages log file for every job that starts. Very annoying.

To separate out those messages, su to root and edit /etc/syslog.conf
remove or comment out
*.info;auth.none;mail.none;authpriv.none;cron.none /var/log/messages
and replace it with
*.info;mail.none;news.none;authpriv.none;cron.none;auth.!=info /var/log/messages

Then you can add the following line to have cron still do its logging, but somewhere else:
auth.info /var/log/auth.info


After that edit, restart the logger and you are done:
service syslog restart