As I don't have a running linix box at present I'm not up on the capabilities of aircrack-ng
Possibles: iStumbler at http:istumbler.net Of the fairly sparse field,this one is probably the most current.
KisMac is a older port of Kismet last released in 2006, but reported to work on Snow Leopard. Haven't tried it.
Another possible useful tool is WireShark. You will need to install XQuartz to use it, as it's an X11 windows app.
A final possibility is to install windows under VirtualBox, Parallels or VMFusion and give it full access to your ethernet cards.