View source for Typical workstation syslog-ng.conf

 # $Header: /var/cvsroot/gentoo-x86/app-admin/syslog-ng/files/syslog-ng.conf.gentoo,v 1.7 2007/08/02 04:52:18 mr_bones_ Exp $
 #
 # Syslog-ng default configuration file for Gentoo Linux
 # contributed by Michael Sterrett
 
 options {
         chain_hostnames(off);
         sync(0);
 
         # The default action of syslog-ng 1.6.0 is to log a STATS line
         # to the file every 10 minutes.  That's pretty ugly after a while.
         # Change it to every 12 hours so you get a nice daily update of
         # how many messages syslog-ng missed (0).
         stats(43200);
 };
 
 source src {
     unix-stream("/dev/log" max-connections(256));
     internal();
     file("/proc/kmsg");
 };
 
 destination messages { file("/var/log/messages"); };
 
 # By default messages are logged to tty12...
 destination console_all { file("/dev/tty12"); };
 # ...if you intend to use /dev/console for programs like xconsole
 # you can comment out the destination line above that references /dev/tty12
 # and uncomment the line below.
 #destination console_all { file("/dev/console"); };
 
 log { source(src); destination(messages); };
 log { source(src); destination(console_all); };

If you find that your workstation's /var/log/messages file is cluttered with every-10-minute cron entries like these:
 Feb 21 07:00:01 oilslick cron[19045]: (root) CMD (test -x /usr/sbin/run-crons && /usr/sbin/run-crons )
 Feb 21 07:10:01 oilslick cron[19097]: (root) CMD (test -x /usr/sbin/run-crons && /usr/sbin/run-crons )
 Feb 21 07:20:01 oilslick cron[19149]: (root) CMD (test -x /usr/sbin/run-crons && /usr/sbin/run-crons )
And, if you want to drop these (for the sake of clarity in your /var/log/messages, one way is to filter out all cron-related messages, by adding the bolded/red lines.  Think twice, though, if this is really, really what you want to do :-O It may be better to continue to log, but just to a separate file which you can review when/as needed
 destination messages { file("/var/log/messages"); };
 <font color=red>'''# We will take out the annoying cron notifications'''                                                                                                                   
 '''filter nocron { not facility(cron); };'''
 '''# We will also remove the annoying spamd notifications'''                                                                
 '''filter nospamd { not program(spamd); };'''</font>

 
 # By default messages are logged to tty12...                                                                                                                                       
 destination console_all { file("/dev/tty12"); };
 # ...if you intend to use /dev/console for programs like xconsole                                                                                                                  
 # you can comment out the destination line above that references /dev/tty12                                                                                                        
 # and uncomment the line below.                                                                                                                                                    
 #destination console_all { file("/dev/console"); };                                                                                                                                
 
 <font color=red>'''log { source(src); filter(nocron); filter(nospamd); destination(messages); };'''</font>
 log { source(src); destination(console_all); };