Face Time 'Abled Icon' for Contacts on iPhone 4

Wouldn't it be great to have an icon of some kind next to the contacts that you 'can' Face Time? I think that it certainly would! At present, when you FT someone that doesn't even have an iPhone 4 you get a very generic message that says 'this number is unavailable for Face Time'. For all I know, they could have an iPhone 4 and just be out of a Wi-Fi reception area! This is just not enough information for me to understand what is happening. There are other questions such as: 1. If a user has an iPhone 4 and they are not available for a FT call, either because the phone is off or they are out of a Wi-Fi receptive area, can I leave a message?
2. If the receiver of the call cannot Face Time, can the call be answered normally anyway?
It will be nice to get these things sorted out, and for whatever functionality of this service that we'd like to see, but isn't there yet.... Well, there'll Be an App for That.