how do I launch "find my iPhone?"
I have lost one of my iPhones. I try to find "find my iPhone" on my MacBook Pro and on my iPad, but I don't find the icon.
MacBook Pro, Mac OS X (10.7.3)
You need to set it up on iCloud. Go into System Preferences and select iCloud, but if you haven't set it up before losing your iPhone it won't do any good, you can't locate it retrospectively!