The most classic form of WYSIWIC that rings a bell straight away, would be remote computer access using Virtual Network Computing (VNC) technology. RealVNC is the most common official software available and is most commonly used by anyone offering IT support off-site or gaining access to another smart device from a remote location.
This program is not the most suitable for Computer Supported Co-orperative Work, containing all the common problems of a ‘strict’ WYSIWIC such as multi-user doing different tasks in synchronisation. I do, however feel that it was extremely easy to use when combined with synchronous communication where users were able to communicate live, the work carried out on the accessed device in a demonstrative/file edit and feedback/problem solving way.
Personally owning 4 ‘smart’ devices including a desktop pc, a laptop, a smart phone and a tablet pc, I sincerely look forward to being able to utilize the program one day to the extent that eliminates the need to carry every single portable device most days when away from home. Requiring all devices to be switched on when accessed is a definitely a bit of a downer to the environment on a social scale, hurting the wallet on a personal level (but the prospects remain rather exciting).