Drupal Tip #4: Crontab
Running "crontab -e" (without the quotes) opens the crontab file where you can set times cron needs to run, if you have the correct access to the server.
With crontab, one can run any command one wants - for drupal, you need to execute cron.php
#m h dom mon dow command 00 * * * * links -dump http://www.uberellis.com/cron.php > /dev/null
m = minutes
h = hours
dom = day of the month (1 ... 31)
mon = month of the n(?) (1 ... 12)
dow = day of the week (0 ... 6) - Sunday = 0
command = the command you want to run at given time
This example will run cron every hour, ie. on minute 00
Other ways include - curl and wget - Drupal includes some script files in the default tarball showing examples of what commands to use for some.