Ya chat snippers do work. If you want to know whether your network is connected via hub or switch, just run the sniffer and check it for 1 or 2 hours. If you see only your and your buddy’s message then a switch is used; if you see others messages as well then a hub is used - in which case you are in a danger as your messages are leaked.

And thats a nice find, will check that and let you know how it worked for me. If you come across any prevention utilities...let me know too.