Question : How to capture wireless tcp packets in passive mode

Hello all,
I'm in a need of "offline" sniffer. That means that I want to collect tcp packets running around my wireless antenna, going to some designated place (or even, if possible, everything). So, for example, I want to capture every packet going to Access point 1 through the air, but without having access to Access Point 1.
I know that it's possible, I found such a tool before, but deleted it for unknown reason :(
I don't need wep/wpa key cracker, just something like tcpdump... So, an ordinary packet (and data) dump.

Thank you

Answer : How to capture wireless tcp packets in passive mode

Software I'd recommend is called Kismet. (Link below). It is a 'passive' wifi packet sniffer. It collects data without making itself known.

http://www.kismetwireless.net/