hub and pcmcia card with promiscuos capability

I have been trying to find a hub lately and purchased a linksys 10/100
hub. When I try to sniff traffic on my network I see nothing except
arp traffic and packets going directly to the computer. I am beginning
to believe that this is actually a switch and/or my ethernet adapter is
not going into promiscuous mode.
Does anyone have any information on a 100 base hub that is actually a
hub?
Is there anybody with experience with a PCMCIA ethernet card that works
in promiscuous mode?