Establish building blocks for driving the activity map on the new front page

The map on the new drupal.org front page (http://infrastructure.drupal.org/drupal.org-style-guide/prototype/homepa...) shows various kinds of activities in (quasi) real-time. This implies a number of things.

1. This means that various events need to be make location aware. The simplest solution would be to take city information from the user that created the event (i.e. the author associated to the node). This might not be 100% valid, but it is probably correct in more than 95% of the cases. It would certainly keep things simple. We'd need to add 'City' and 'Country' to the profiles and map that to geo-coordinates.
2. Even if we take the city information from the user profile, we probably need to maintain a list of the last x events that we want to show on the map. We need to figure out how we're tracking those -- e.g. should we create a map_queue database table that we can inject updates in, and that drives the map?
3. We need to identify what map technology to use, and how we can drive it using Javascript. Mark Boulton seems to be using a Flash applet in his mock-ups, but we might want to use a Javascript based solution instead.

We can use this issue to discuss the general direction, and then we should probably break this issue in 3 issues that are linked to this parent issue.