Whether they realize it or not, many people are already in the "cloud." The most familiar example is the deceptively simple Google search. In fact, these searches harness powerful remote processors and massive databases to troll for fish in a vast sea of information.
Many online services follow Google's model, offering free access and selling advertising to generate revenue. In this manner, Google, Yahoo and Microsoft provide e-mail services and messaging - while social-networking sites such as MySpace and Facebook give users free accounts to help them meet others.
But some companies are also moving to two-tiered models like Flickr's, charging fees for premium online computing services, while offering more basic services free of charge.
Zoho.com, for instance, provides a free suite of Web-based office applications, but charges $5 to $80 per month for additional server space. And Intuit charges monthly fees for online versions of its financial software - $2.99 for its Quicken personal finance program and up to $49.99 for its business accounting program, QuickBooks.
Kasameyer, for one, has been happy to pay for Flickr's premium service. The Johns Hopkins nursing student has made a number of friends through Flickr, and it saved her photos when her laptop crashed. "All my best stuff is backed up somewhere else and not just on my crappy computer here," she said.
But her experiences haven't been all positive. When a church failed to ask permission to use one of her photos in a brochure, she let it ride. But she was less tolerant when a German manufacturer of metal corsets used one of her photos on its Web site. "I had a hell of a time getting them to take down my photography," she said.
Her problems illustrate two major concerns about cloud computing: security and privacy.
Data stored on centralized networks is an appetizing target for hackers, who can reach in from anywhere in the world. Network hubs could also become targets for terrorists or unfriendly countries bent on disabling the nation's technological infrastructure.
Last Friday, IBM announced it was helping a Chinese company to build China's first cloud computing center. IBM said the center will serve other Chinese companies, but experts worry that U.S. technological resources might one day be outsourced to such centers.
"Just like the highway system or water system are important infrastructures, so is this computing grid," said Carr. "It raises questions about national sovereignty that haven't been hashed out."
