How to disable Magento crontab job

I'm not sure if this is a recommended method or not, but it seems to work for me. You can create your own extension for the purpose of overriding cron and adjust the settings in the config.xml. To disable a core job, simply enter an empty cron_expr node.

For instance, We don't use the stock newsletter functionality in our store, so I wanted to disable the newsletter_send_all job. To do this I put the following in my config.xml:

<crontab>
    <jobs>
        <newsletter_send_all>
            <schedule><cron_expr></cron_expr></schedule>
        </newsletter_send_all>
    </jobs>
</crontab>

As I said, this seems to work well, but I'd welcome any feedback if someone thinks this is a bad idea for any reason.