In my 2013 CRE tech predictions, I suggested that CRE Data Visualization would made major advancements in 2013. So, of course, I am going to point out examples to make myself look smart....
One of the best examples of this HUGE opportunity is 2nd City Zoning.

From NextCity.org:

In essence, the map allows residents to answer the question, “what can I build on this property?” Punch in an address to discover how a building is zoned, and see a human-readable description (written by us!) of what that actually means. (For instance, I live in an “RT-4” district, which typically features “two-flats, townhouses, low-density apartment buildings, single-family homes.”)

On top of the map, we’ve also distilled much of the zoning ordinance into a beginner-friendly cheat sheet, so residents can dig into the particulars of their property’s land use and density rules.

These rules are what actually limit how dense a building can be and what you can do with it. We’ve done our best to cut through the legalese and explain how they work. Ever wondered what a building’s FAR is? Enlightenment awaits.

By the way, the app’s homage to SimCity is critical to making zoning digestible to humans — for many, the video game is the only cultural touchstone people have for zoning.

Besides looking up a specific property, you can also use the app to explore Chicago’s zoning patterns and learn why the city’s urban landscape looks the way it does. That drive-through bank slicing through the walkable storefronts? The alderman carved out a tiny zoning district for that property. That industrial corridor butting up against downtown lofts and boutiques? There’s a planned manufacturing district keeping it around. That sudden drop-off in high-rise apartments? Anti-development NIMBYs downzoned the adjacent block.

For anyone who has had to peck and click their way around any Municipality's GIS mapping and planning, you will understand how nice a decent Google Map can be.

2nd City Zoning is part of Open City. Open City is a group of volunteers that create apps with open data to improve transparency and citizen understanding of our government.

A couple other KILLER visualization apps created by OpenCity.org include ChicagoBuildings.org, a vacant and abandoned building locator map, and HowsBusinessChicago.org a dashboard of economic indicators for the Chicago area.