Wirelessly posted (Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_2_1 like Mac OS X; en-us) AppleWebKit/533.17.9 (KHTML, like Gecko) Version/5.0.2 Mobile/8C148 Safari/6533.18.5) I have two iDevices, an iPhone4 and an iPad. Both have updated firmware. I've activated the new free Find My iPhone on my iPad. How do I activate it on my iPhone? Can I use the same Apple ID on two devices?