If you need to monitor cron jobs to verify they run for a particular user open the terminal and type, $USER being the currently logged on user:
$ tail -F /var/log/syslog | egrep 'CRON.*'$USER
$ SOME_USER="root" $ tail -F /var/log/syslog | egrep 'CRON.*'$SOME_USER
You could also call tail using Python in a timed while loop with subprocess in a thread and post results to a GTK list or create a shell script so you can call the command something shorter, like cronwatch.