Motivation:

No matter what you say, the look does matter... How much time, money, energy and bad feelings could be saved by having a virtual pre-date over the video phone...? Let alone security!

The feature:

The two virtual daters can use their IP phones to first conduct a normal voice phone call. Then at their will they can choose (on-the-fly) to upgrade the call to a video call. The offerree may refuse to upgrade (while keeping the voice part of the call going) or may choose to accept the video upgrade, but only in a receiving mode (!) or may choose to fully accept the upgrade (i.e. both send and receive). In any case the voice part of the call is not impacted.

How this can be accomplished:

Figure 1 below illustrates how this can be accomplished.