I've found out about this other really nifty tool for networks. It's called NeDi (for NEtwork DIscovery), and is used to inventory devices connected to a network, the ports available on network devices, routes, modules, and other kinds of details that are just fun to have, or really useful to refer to from a central repository. It's nice too because it installs extremely well on Ubuntu; a wiki entry even exists to give a quick how-to on the installation and configuration process: https://help.ubuntu.com/community/NediHowTo.
Once you've gone through the steps described in the wiki entry, and run your first nedi.pl -cob (and waited the a minutes if you've happily asked it to map your whole corporate networks (oops!)), you can access the web interface and view all the information that was gathered, such as devices routes, firmware versions, models, serial numbers, and what end-user devices are connected where.
NeDi is also apparently part of the GroundWork OpenSource products, which is a pretty interesting suite of software if you want to roll out systems monitoring in your location.