9BitLabs Simple Network Area Prober (SNAP) v1.02
This tool uses your Wi-Fi network to scan your local area network and see what else is nearby. It will list all the hosts that are on your subnet. You can drill down and see the IP and MAC addresses of each host, along with the name of the vendor of the network adapter and whether the host will accept network pings. You can also do a quick port scan and see which lower-numbered ports are open and accepting connections.
For example, when I used SNAP on my home network, I found that my Roku video streaming box had an open port of 8080 (which is probably not of much interest for business purposes but is good for cocktail party chatter).