Speedrack is a single-node cron system with an attractive web interface, execution history, and configurable notification via email. It's really easy to install, use, and maintain.
If you're doing it right already, with a combination of cron / real monitoring / real task history and more, then Speedrack is decidedly underwhelming. However, if you're not quite getting by with your jumble of cron scripts, but learning and managing a handful of big applications sets off your overkill-radar, then Speedrack might help you.
It's free and open-source (BSD). Speedrack's documentation will give a little more information. Skim the intro, install and give the demo a spin (one minute if you have python already), and you'll know immediately whether it's a good fit for you.