In building technology for campaigns -- electoral and otherwise -- one of the most difficult tasks is determining which congressional district you're working in. The databases which hold such information are generally out of date, proprietary or without APIs. Worst of all, they're tied only to existing voters and their addresses, versus a specific location on a map. This means that it's next to impossible to target unregistered voters with relevant campaign information. This also means existing voters have to look-up their district with one of these clunky tools before calling their representatives to ask for change.
My friends at Mobile Commons just fixed this problem, releasing an open source database for querying congressional and state legislators by latitude and longitude.
As a former campaign worker, I see this new tool being incorporated in applications like the Barack Obama iPhone app or a mobile application for Union outreach workers, giving Organizers the ability to quickly and accurately ID a constituent's congressional district and deliver relevant information.
Whatever the tool is used for, I'm excited. This could end up being a really powerful tool for Democracy 2.0.