[UPHPU] automatic calculation procedure?

[Connor Boyack]

Ladies and gents,

I am developing a site where I need to rank things based on a certain
calculation.  The easiest way to explain this is using digg.com - they have
an algorithm that calculates how many diggs there have been in a set amount
of time, and if it meets their criteria, the post is then flagged to be
posted on the front page.

I need to calculate something similar to that situation, and I'm not sure
how to do it.  It will need to be automated, so that every minute it checks
the other listings, and determines if they are to be flagged or not, based
on some calculations.  How can I do this?  Does MySQL have something that
lets you do this type of thing, or do you have to run a cron job on a php
file that has the calculations?

Any ideas?  Thanks in advance for your help.

Connor