It's only been six weeks since the breakthrough Internet of Things (IoT) World Forum in Barcelona, but the momentum to build web-enabled Smart Cities appears to be crescendoing toward a tipping point.

Just this past week, I participated in two highly energized Smart City forums in "old" cities that attracted executive-level leaders from government, vertical industries and technology providers. At both -one in Hamburg and the other in Amsterdam -I experienced first-hand the growing use of digital devices connected to networks that enhance the experience of citizens and businesses and also improve sustainability and performance.

During the panel discussion at the Amsterdam Meeting of the Minds conference, which was linked via Cisco Telepresence to U.S. city leaders in Boston, Washington DC, San Jose and Detroit, I was asked, "Are Smart Cities Real?"

To me, the answer is tangible. With aging and shrinking populations, combined with 60 million people flocking to urban centers each year, municipalities that don't embrace the digital economy will lag behind. Yes, it's abundantly clear that competition today is not so much between countries as between cities -old and new -vying for younger talent.

Leading municipalities, such as Barcelona, Amsterdam, Hamburg, Nice, London, Chicago, New York City, Busan, Dubai, Songdo, Toronto and others, are regenerating themselves with real-time, networked applications to improve everything from traffic flow and parking to water usage and energy consumption. In some, passersby can instantly find nearby restaurants, shopping deals, mass transit and more at their fingertips through connected mobile devices.

Wherever I go, I hear that "IoT is now!" Why now? First, proven results in role-model cities are inspiring strong visionary leaders everywhere to transform their cityscapes into digital networks by connecting the unconnected. Second, a collaborative ecosystem of technology providers has emerged to connect devices in an IP enabled mode, to the Internet through open platforms such as Wi-Fi. Most importantly, there's a virtual explosion of killer apps to address nearly every conceivable need of citizens, cities and business at the physical edge of their location; some 15,000 apps are released weekly.

In Hamburg and Amsterdam, it was validated that IoT adoption is spreading to mature cities just as rapidly as to brand to new "greenfield" metropolises just being born. For example, Hamburg, Germany's second largest city built around the Elbe river with nearly 2 million residents, dates back to the Holy Roman Empire. Classic stone buildings, cobblestone streets, stone bridges and Europe's second largest port add to its historical charm.

Hamburg First Mayor Olaf Scholz and Senator (Minister) Frank Horch (Innovation, Transportation and Economy) hosted Germany's first Smart City Summit at the majestic Townhall, circa 1886, but the focus was on how to further rejuvenate the city with new generations of IoT solutions citywide built on expanding web-based infrastructure.

During a brisk walking tour the next morning of HafenCity, Hamburg's innovative, award-winning "city within a city" rising like a Phoenix from the ashes of old warehouses and docks amid port operations, our local team saw the infinite possibilities for IoT integration. Our "tour guide", HafenCity CEO Jurgen Bruns-Berentelg, passionately embraces the IoT vision. I am sure HafenCity, with its 163 acres (147 hectares) of newly intertwined residences, shops, restaurants, offices, parks and canals, will evolve into an IoT showcase for the 21^stcentury.

Then, we were treated to a boat tour along the Elbe of the massively complex port facilities by Hamburg Port Authority CEO Jens Meier, another passionate believer in IoT solutions, both to improve personal experiences and especially business operations. While motoring by containers stacked high on docks, enormous cranes, cargo and cruise ships that dwarfed us, Jens saw the many possibilities where IoT solutions, combined with Big Data analytics, could improve inventory, flow through, traffic, efficiency, productivity and the environment. Plans are in the works.

In Amsterdam, while on stage with Deputy Mayor Carolien Gehrels and linked via TP to city leaders in the United States, we focused a lot on the requirement for what I call public-private "participations" to help jumpstart IoT growth. Co-investment helps spur action.

I was born and raised in the Netherlands, and Gehrels reminded us that the Dutch are models of "collaboration" because citizens have had to work collectively to combat what she calls their "three crosses" -fire, disease, and water. When it comes to IoT, where the centuries-old Amsterdam already has an installed IoT base to improve sustainable working/living, public spaces and mobility, they are exploring new LED-connected street lighting. Their broader vision is to connect all citizens by 2018.

It's clear to me that the Smart City movement continues to gain traction, even in old cities being renewed.