In response to changing customer needs, the advent of new technology and increasing financial pressures, NYC311 has evolved over the past few years from a call center to a multi-access, multi-channel source for information. The evolution remains grounded in 311's core mission to provide quick and easy access with the highest possible customer service, and is part of a larger strategy driven by customer needs and financial imperatives: migrating from a "one-to-one" mode of service delivery to a "one-to-many" information platform spanning multiple channels in the way the public wants to consume it. The execution of that strategy is under way and has yielded an expansion of service delivery from exclusively phone-channel to Internet, social media, apps and more. The following is a brief introduction of the various communication modes NYC311 uses and the path taken to deploy them.

311 Online: Moving the entire catalogue of information available to call-center reps to the Internet allows customers to access 311 anytime and anywhere. Designed, developed and implemented through a combination of internal city resources and contracted vendors for specialty functions, 311 Online was built and deployed in less than one year, and provides a foundation for further expansion of Internet offerings, as well as a destination point for city government information and services.

Opening city data: Through the Big Apps contest, which challenged developers to create public applications, NYC opened more than 170 datasets in 2009. The contest sparked innovation and created new apps to explore New York and interact with city government. Big Apps was a low-cost way to provide data and let the marketplace decide what to do with it and how to distribute it. Ultimately, the city better understood how constituents access and use data.

Micro-blogging: Originally intended as a companion to the launch of 311Online, the NYC Twitter presence (311NYC) evolved into a viable info-push to more than 7,500 New Yorkers. Designed and built by a call center representative and staff analyst, the city's Twitter effort proved to be a low-cost and easy-access channel that has enabled greater communication and also provided NYC311 with a new customer listening post. Reviewing, evaluating and responding to tweets has changed the interaction with customers while making services more accessible.

Inviting the public to correspond: In the spirit of opening a new public square, New York introduced "The 311 ," a blog open to employees and customers. Using free technology (WordPress), the blog allows 311 employees to share information in a relaxed and informal manner, engaging customer comments, critiques and communication.

Pushing information: The city launched "NotifyNYC ," a registration-and-notification process that distributes information using text, email or voice messages for general citywide information, as well as geographic-specific updates. NYC311 will expand the service for potential topics such as parking, recycling collections, and notification of school and government office closure.

Apps: The NYC311 iPhone app was designed and developed internally by the Department of Information Technology and Telecommunications in 2009. Using the iPhone app, customers can report graffiti, potholes and other quality-of-life issues quickly through a familiar interface. The GPS function on the iPhone simplifies the entry of address information and saves time while submitting the data into the same stream used for service requests reported through the call center.

The evolution of service delivery continues, with enhancements for new channels and exploration of crowd-sourcing, auto-text and interactive mapping under way. From initial call handling for non-emergency government services, to an ambitious expansion fulfilling on the promise of "your city, your needs, your number," NYC311 has changed government service delivery.

• Read the main story, "The new public square," to learn how New York, Boston and Miami-Dade County are engaging residents through e-government and mobile applications, including social media.

Joseph Morrisroe is the executive director NYC311 in NYC's Office of the Mayor.