Easy to scan for Wireless Networks directly from your Mac OSX Terminal.
1. Launch the Terminal and type the following command (you have to do this once):
sudo ln -s /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport /usr/local/bin/airport
2. Enter your Mac OSX Password
Now, to scan for and find all wireless networks within range, type the following:
The list returned will show all available wifi networks and their router name (SSID), the router address (BSSID), signal strength (RSSI), channel, and security types used by the network.