I disabled the SSID broadcast on my wireless router, obviously no networks showed up on my Wi-Fi page on my iPhone, but even when I pushed the "Other… " button on the iPhone Wi-Fi page, put in the SSID, security type, and password, my phone "could not find the network." Everything worked fine with the SSID on. There's no MAC address filter on my router, or any other configuration on the router I can think of that would negate use of iPhones minus SSID broadcast. Could it be that security enabled on router is WAP2 personal and WAP2 personal is not security option on iPhone ("WAP2" is option, but not "WAP2 Personal")?