I use What's Running a great deal so I can know what is going on within my box but here is a small free utility which is a handy way to get a quick list of all the devices connected to your network. They are listed by IP address, along with information about each device. It quickly scans all IP addresses in a range that you specify, then specifies whether a device is present at each address. For each device, it lists the status, the machine name, NetBIOS information, ping information, and MAC address. I usually have difficulty keeping track so this can be useful.
Moreover, the program not only scans your network but it also gives you a set of tools that lets you shut down PCs remotely, use the "Wake on LAN" feature for any PC whose network card supports that capability, and connect to remote PCs via Radmin, if it's installed. I have used another remote site so this would allow an opportunity to combine functions in one use. You can also apply some operations, such as shutting down remote PCs, to a group of computers, not just individual ones.
This tool could be effectively used and handy.