Facebook Chat Monitor Sniffer is a utility that can record chat conversations. It only works with the Facebook chat and uses WinPCAP to capture the packets that go around your network. It then detects which ones are from the Facebook chat and reformats the packet information, so that only the important stuff is displayed.
Unlike IMMonitor's other Facebook sniffer, IMMonitor Facebook Spy, this tool can scan and detect Facebook chat messages from any computer in your subnet. The other tool could only detect chatter coming from a single IP address at a time. Furthermore, Facebook Chat Monitor Sniffer doesn't even ask you to scan your home network. All you need to do is click on "Start" and the application will start detecting packages. I found it very easy to use and it simply worked. As soon as I started scanning, I sent some messages on Facebook and they were added to the list of captured messages one after the other, with my computer's IP address next to it. Some of the messages even said who they were from.
The trial version of this app will only show you the first 10 messages captured since the scan was started. It is a good limitation, so that people can try the program and see what it can do, before they decide to buy it.