It struck him not only as absurd, but eminently fixable, and with a marketing angle perfectly matched to the corporate quest for better health and safety performance, while pruning unnecessary in-house costs.
From that moment WhosOnLocation was born.
Research showed many companies were using a mish-mash of physical visitor registers, magnet boards, email "out of office" messages and off-the-shelf visitor management systems that didn't talk to each other.
"They needed an all-in-one solution with the ability to access critical information," says Whitaker-Barnett.
Today, WhosOnLocation offers a solution that you can have up and running in a day or two, anywhere in the world.
Hosted in the cloud, the system allows staff and visitors to emerge from the burning rubble secure in the knowledge that everyone registered as being in the building can be verified as safe or not by texting a single word - "safe" - using the firm's newly launched add-on product, mobiEvac.
Other features include systems for managing staff whereabouts, visitors, contractors and ID cards.
"Our focus is on the security, health and safety angle," says Whitaker-Barnett, but the system's potential comes from early recognition of the potential of cloud computing.
An avid follower of "cloud heroes" such as Kiwi accounting solutions firm Xero and Salesforce.com, Whitaker-Barnett says WhosOnLocation blows away the traditional economics of visitor management systems.
"The point of difference is fast deployment, and one instance of the software, which is multi-tenanted."
Its early uptake in New Zealand was spectacular. For early credibility, Whitaker-Barnett figured a government department would be a great first customer.
He offered the service to one major agency free for six months in 2007.
They loved it so much they became the first user, and the proof point for a string of sales to other users, even including the Department of Corrections.
Corporate clients include food company Griffin's, Postie Plus, Frucor, ADT/Armourguard, Assa Abloy, Northland Regional Council, Meridian Energy, and many others.
The system has also found a ready market in security-conscious South African cities, is used in Toronto by Unilever, one of the world's largest multinationals, and is to be used at pre-America's Cup events.
As a result of this clear global potential, Whitaker-Barnett and his principal co-investor Victoria Armstrong spent time last month on a New Zealand Trade and Enterprise hosted tour of prospective customers in the US and Canada.
The company had the chance to meet representatives of the US Department of Homeland Security, the US Urban Search and Rescue Service, General Dynamics, Lockheed Martin, and Boeing.
"No one does what we do in the US market, particularly verification and people safety, and at our price point," Whitaker-Barnett says.
All this means the plan to become "the Apple of the people presence management space", a half billion dollar company - that's US dollars - in five years, and a billion dollar company in 10 years, appears at least credible.
But first things first, and Whitaker-Barnett says the main focus for the next 12 months is to raise a minimum of US$5 million in venture capital "to penetrate these global markets quickly."
A share float is on the agenda, further down the track, though he is cagey on the merits of an NZX listing versus listing in a deeper, more tech-savvy market.
One thing that won't slow down WhosOnLocation is the intellectual property rigmarole that soaks up time and legal fees for many advanced technology high-growth wannabes.
"Our IP exists in being first and fastest to market," says Whitaker-Barnett. "Unless it's hugely innovative in the software space, it's better to focus on market expansion to stay ahead."
