[jmsguy]

Not unless (a) your PC is routing traffic or (b) your PC is connected to a hub vs. a switch [1].

Unless one of these things is happening (even if your card is in promiscuous mode), those packets won't make it into your machine.

[1] http://www.webopedia.com/DidYouKnow/Hardware_Software/router...

[whoopdedo]

What about wireless traffic?

[dr_zoidberg]

Wireless cards can be put in promiscuous mode, and you'll see the packets that reach your computer, but maybe not all the traffic of the wireless network - this is known as the hidden node problem[1].

[1] http://en.wikipedia.org/wiki/Hidden_node_problem