WindyCitizen.com is “a crowd-powered front page for the Windy City” that “brings Chicagoans the best of the local web by letting them share, rate and discuss their favorite local news, photos, videos and more.”

“We’re searching Twitter constantly to keep you up to date with the conversation about the IL-5 special election. The graph above lets you track buzz about the candidates over the last two weeks.”

Their Windy City Twitter Tracker mashup uses Open Calais as a named entity recognizer to track Tweets about candidates in the special election to fill the US House seat for Chicago’s 5th district that that Rahm Emanuel vacated. Calais might be overkill for this, since there is a small set of known candidates, but it’s an impressive semantic mashup nonetheless.

The Windy City Twitter Tracker is probably written to be easily repurposed, judging from the Web site, which describe it as currently tracking the “Race for the 5th”. The mashup is credited to Whattech.