I installed MarcoPolo on my PowerBook today. It lets you define rules that trigger switching network locations based on what hardware is attached. If my KVM is attached, the PowerBook switches to my “Home (wired)” location. If I remove the KVM, and my wireless access point is in range, then it switches to my “Home (wireless)” location. If there’s no KVM and my access point isn’t in range, it switches to the generic “Automatic” location. Pretty cool little app.