Conversations with maps
Not to be thwarted, I did a websearch for the terms "map", "shared", and "chat". In the results, I found an AJAX/Google Local implementation from midnightcoders.net. The site allows shared map manipulation during chat, but I was the only site visitor.
Last, I noticed that a somewhat similar site, mapable.com, recently went live. Mapable allows users to create georeferenced chatrooms. The mapable chatroom does not allow shared map manipulation; the site geolocates users, posts a marker at their location, and their chat messages appear next to their markers. For an example, you can visit the site, or a test I created here.
I will withhold substantial analysis of these conversations with maps, other than the following few sentences. The primary purpose of maps is to encode and communicate spatial data; the ability for multiple users to interactively manipulate and share geographic information in real time is a powerful form of communication. Given similar functionality in virtual globes, I can imagine: taking a classroom of students on an interactive virtual excursion to Yellowstone; discussing site location and decisionmaking among widely-spread builders, suppliers, planners, and stakeholders; scientists meeting online to examine the evolution of hurricanes; and dispatchers and field personnel allocating and placing resources, in precise, possibly non-geocoded locations, during an emergency.