Wez Furlong wants a bit more out of his PHP script, naemly the ability to be able to process things in the background without tying up or immediately using the script that's running.

In my recent talk on sending mail from php I mention that you want to avoid sending mail directly from a web page. A couple of people have asked me how to implement that, and one of the suggestions I have is to queue your mail in a database table and have some other process act on that table.

He gives a solution that's a bit more optimized for this solution than just polling the same information over and over - using PDO and LISTEN/NOTIFY processing along with transactions to make the CLI script only grab information when there's something new.