Example Monit Configuration with Mongrel
onit is great for keeping your services online. I use them for keeping my collection of slices online when I am asleep.
The example monitrc is a great starting point of listing the services which you should be monitoring.
One thing: monit can have its own little http server which runs internally. This is off in the example config as you have to explicitly enable it.
I hope to release a monit config generator gem in the near future which makes this a lot quicker.