[josephruscio]

I hack on the aforementioned Silverline at http://librato.com, and we provide system-level monitoring at the process/application granularity as-a-Service. (We also have a bunch of features around active workload management controls, but that's out of scope here). It actually works on any server running one of the supported versions of Linux, not just EC2. Benefits of going with a service-based offering are the same as in any other vertical, you don't need to install and manage your own software/hardware for monitoring.

Here's an example of the visualizations we provide into what's going on in your server instances: http://support.silverline.librato.com/kb/monitoring-tags/app...