Hey Phish,
I agree that disabling SSID broadcast isnt the best way of securing your AP. But it does prevent people from just stumbling upon it. If you are broadcasting ANYONE can see the network, even if they arent looking for it. If you arent broadcasting then you actually have to be looking for a wireless network to find it. Its one layer of security. Although it can cause problems with WPA sometimes (I personaly have never experienced any trouble with this, but have been told it can casue problems)