Currently I'm consulting and doing some script writing for a performance project called "The Mischievous Ant." A director here at Queen's is working with people from the Rhode Island School of Design (RISD, pronounced RIZZ-dee) to make a theater piece with some technology associated with it.
In thinking about this it seems to me that there are three broad categories of using new technology in a performance.
Technology for the audience only
This is some technology that is part of the performance that the characters do not react to. For example, there might be a video screen above the stage that shows what the characters are thinking. It helps tell the story.
This also includes technological ways in which the audience can affect the performance. For example, the way they shift in their seats can affect the lighting or how characters move. The characters are not aware of the presence.
Technology in the reality of the characters
This is technology in the world of the play. Characters interact with it. For example, there might be characters who have TV sets for heads, and the TV sets "speak." The characters treat this as normal, as they are familiar with this part of technology in their world, as we are with cell phones in ours.
Technology that the characters react to
The technology is a new part of the world of the play, and the characters react to the new technology appropriately: with fear, awe, etc.