WiFi Radar is a utility for managing, scanning, and auto-connecting to WiFi profiles. It enables you to scan for available networks and create profiles for your preferred networks. At boot time, running WiFi Radar will automatically scan for an available preferred network and connect to it. You can drag and drop your preferred networks to arrange the profile priority.
WiFi Radar is tested to work with Centrino´s WiFi card IPW2100 but should work just the same for any iwconfig interface.