Assuming 9 homes with 1-2 trigger objects in each, we will need from 10-20 video vignettes. These will be embedded in flash movies and loaded into an interface that pops up when triggered in-game. The interface that holds the movie should be tied conceptually to the game environment. For example, say the trigger object is a dilapidated sofa. When the trigger action occurs, an old gold-leaf picture frame pops up and where a painting would be expected, the vignette begins to play.
The vignette should be a 15 to 30 second (max) artistic rendition of a simple concept. The idea is to imagine what life might have been like in this desert suburban environment and communicate that artistically. For example, associated with a television, the vignette might be scenes from around the dinner table intercut with scenes from Mary Tyler Moore (sitcom) and children swinging. Remember that Playas was abandoned in the mid to late 90s, so contemporary material, unless it's unrecognizable as such, won't work.
Some vignettes might be associated with the future use of Playas, instead of everyday scenes from it's past. Images of anti-terrorist training exercises (we have footage of this), politicians, world trade center collapsing and expanding (ie manipulated), etc.
A third strategy is to mix past and future together, but this has to be done carefully to be done well.