Apple Thoughts: Who is Ready for FaceTime? Find Out With FacePlant

"By now, everybody who owns an iPhone 4 knows how cool FaceTime is. They're also probably frustrated with the fact that a) you need to make a call at least one time in order to verify that a friend has an iPhone 4 and can actually do FaceTime chats, b) you can't see when friends are on Wi-Fi and ready to talk, and c) you can't leave them a video message when they're off a Wi-Fi network or have their phone turned off."

This app will certainly help you figure out who can "FaceTime" with you. The app is called FacePlant, and it isn't out yet in the app store so I haven't had a chance to try it out, but the basics are that the app goes through your contacts and if any of them are registered with FacePlant they will show up on the contacts list. If they are willing and able to talk they have an orange bar surrounding their name, if not they show up with gray around it. You can also leave them a video voicemail. No word on when it will be released other than "soon," but it will be free.