Cloud computing has been called the next big thing. The startup's best friend. An idea whose time has come ... or might not have arrived just yet.

If you use Web mail, share snapshots through Flickr or collaborate online with LotusLive or Google apps, you're already in the cloud. As an Internet-based computing solution that houses data, applications and hardware in its own venue instead of your local machine or data center, cloud computing has the potential to overhaul even the most basic IT assumptions for businesses. More and more companies will choose cloud computing as the way to expand their operations and conserve resources. And here are some reasons why:

• Thanks to fast connections, a remote cloud computing center can supplement or even replace an on-site data center, saving money on energy costs and freeing IT staff from routine maintenance duties.
• It can save money on licensing. With a software as a service (SaaS) option, pay-as-you-go billing can reduce startup and upgrade expenses such as individual application-licensing fees. Customers can be billed based on server utilization, processing power usage or bandwidth consumed.
• With necessary systems already in place in a cloud center, it can dramatically scale up computing capacity within hours when peak needs arise, instead of the weeks required for in-house expansion.

But for all of the advantages, you still might wonder how this ethereal entity can provide a secure and reliable platform for your most confidential data as it travels back and forth across the Web. Those online applications and databases you use for free just seem so... public.