Just saw this article in The Register and it made me think of an old idea for teaching what life in Rome was like circa whenever. Basically you start with the information in "Ancient Rome 3D" and you use it to create a mediated MPORG in which the students can participate as individual characters. I use the term "mediated" because I think it is important to allow the teacher to control plot lines and external events to illustrate specific points such as food riots, etc. The idea is not to replace reading and discussion, but to help provide a more immediate context for these more traditional types of instruction.
Obviously this same technique could be applied to just about any time and place for which we have enough data to create the 3D environment. You could hit all the high points, Athens circa 500 BC, Tenochtitlan circa 1400, San Francisco circa 1965. What is really exciting is that, technically, this should be relatively easy to do. That is to say, it could be done with an awful lot of work by artists, programmers, writers, etc. like any game, but we don't need to invent any new technologies to make it happen. All we need is a business plan whereby somebody can make money off of this idea while simultaneously providing it to schools for little to nothing.