Does anyone know of a script that will create a page similar to the Cron module in Webmin? I'm trying to figure out how to add/modify jobs through a web browser.

Been looking for that myself too!!!

ANYONE!!! PLEASE!!! :D

I can't imagine why Cobalt didn't include something like this.

Yeah me too :(
The only thing you can do is manually put shell scripts in /etc/cron.*

* being daily, quarter-daily, hourly, etc

just use crontab -e :)