This is a PSA (Public Service Announcement) for folks like myself who are using earlier versions of iOS. In April 2014, FaceTime stopped working between devices unless both were using more recent iOS versions:
http://support.apple.com/kb/ts5419
I'm hanging onto iOS 5 for as long as I can (because of a con in all subsequent iOS versions, which I mentioned here), so my usage of FaceTime will now dwindle even further from "almost never". However, it's still a shame to lose that functionality, unless you're willing to upgrade your iOS version -- I had to hunt this down recently on one of the "almost never" occasions when I was trying to use FaceTime.
