One of my submissions to the 10K Apart competition is this Twitter connections application. Each point you can see is a different user that you follow. When you click on a point you get to see the latest tweet by that user and other information about them.
The size of each point in this version is related to the amount of tweets each user has sent. I think I prefer this to having all the points at a similar, arbitrary size.
All the code used in this example is under 10KB.
Soundtrack is "This Space" by Royksopp.