I've used LANsurveyor for at least 6 years. It makes the job of managing many machines on large or multiple networks much easier, as it literally gives a map of the networks and all the machines on those networks.

Visualize a map that begins at your router with paths (lines) to your switches and then paths to all your machines. All subnets are numbered, and all the machines are identified. These "all machines" include computers, printers, network devices, and essentially anything on the network. Now imagine that the computers are characterized as well by name, number and services. Imagine that the computers running Retrospect and Timbuktu all report in with even more info, and if they have the Responder (responds to LANsurveyor queries) they report even more info. All your network devices respond too, with SNMP data.

It's like a road map and an atlas, but for your network. Whether your network is a Class A (the equivalent of a continent) a Class B (a large country), a Class C (a small country) or even smaller, this gives you a graphic picture of what is there. It has made my job (in networks of all three classes) much easier.

Current drawbacks: Version 7.1 doesn't work with 10.3, although the beta version of 8.0 does. I'd like it to integrate with some FIS/GIS package for better management. There is a good manual, but no tutorial. Would be nice to have some integration with NetMinder Ethernet.