root@myserver:~# apt-get install automysqlbackup
root@myserver:~# crontab -e
# m h dom mon dow command
5 4 * * * automysqlbackup
root@myserver:~# automysqlbackup
root@myserver:~# cd /var/lib/automysqlbackup/
root@myserver:/var/lib/automysqlbackup# find .
.
./weekly
./weekly/wikidb
./weekly/information_schema
./daily
./daily/wikidb
./daily/wikidb/wikidb_2012-06-14_16h03m.Thursday.sql.gz
./daily/information_schema
./daily/information_schema/information_schema_2012-06-14_16h03m.Thursday.sql.gz
./monthly
Result! No longer need to write a custom cron script each time.
Project homepage: http://sourceforge.net/projects/automysqlbackup/