Here’s an idea many may have been looking for especially if you want to reach a streamlined set of followers for any reason. Filta which some have compared to Facebook’s Graph Search allows you to look up or find your twitter followers who are interested in a particular subject.
This could come in handy on several fronts including research. So say you want to reach a group of people for the purpose of sampling their opinions on a subject matter, you could use this tool. It could be very useful for social purposes like meeting up a specific set of people in a new location.
There are concerns though that Twitter may decide to build in an application that works just like this maybe in a more flexible way in future. Right now you can login using your Twitter account on Filta.