A week or so ago, I posted a quick hack using the Google Social graph API showing how to generate a list Common Friends or Followers on Twitter, so that you could look up which folk would see, in their Twitter timeline, a conversation between two other people on Twitter. (A hosted version of the service is now available here.)
At the time I also generalised the code so that you could look up the extent to which any party could see the conversations between two other parties on twitter, in stream. This is another single page web app and it can be found hre: Twitter in-stream eavesdrop.
It looks like this:
Very simple, very quick… there is nothing more to it than what you find if you View Source… (In fact, there’s more than you need if you View Source – there is also a Google Analytics tracking code in there…)