OSX can capture WiFi packets using only tcpdump (and without needing a clunky interface such as KisMAC). Used for testing security strength of home WiFi setup.

kapture.sh

#! /bin/bash

# This is for Mac OSX only.
# =============================================
# explanation of arguments used with 'tcpdump':
# =============================================
# -y IEEE802_11_RADIO => makes it capture __WIFI__ packets, turns resultant file
#                        into a dump which can be read by aircrack-ng, etc.
#
# -I     => puts interface into monitor mode (required to capture packets)
#
# -i en1 => sets Airport card as the wireless device (pretty much required for
#           OSX unless you have a different wireless card)
# 
# -w datadump.pcap => can be any filename. will write packets to a .pcap file
#                     (instead of STDOUT)
# =============================================

tcpdump -y 'IEEE802_11_RADIO' -I -i en1 -w datadump.pcap