Mac users interested in Packet sniffer via wireless network generally download:
Eavesdrop is a free TCP packet sniffer for the Mac. The app allows you to capture traffic on your home network. It is not a very advanced application at this time, and it has some limitations, but it still is a nice app to illustrate how a sniffer works, and it can even be used to analyze some traffic, if you happen to know what you are looking for.
