I spent a few long nights setting up Nagios and Cacti to monitor outages and trends on our systems.
We're a small shop, and until recently it was only me doing things. while Nagios was good at letting me know after problems came up, I'd frequently go days without remembering to check Cacti to help see problems before they fully developed.
I practically live in my GroupWise system during the day, and decided that adding a System Monitoring tab using the new web panel feature would give me a handy quick view during the day.
So I set up a tab with a single column, two web panel view of the Cacti and Nagios web pages
Now I find myself checking both systems several times a day, instead of waiting for a text message telling me of a new problem.