Cloud computing can seem amorphous and hard to grasp -- billowy white puffs of IT infrastructure. The best way to bring the trend into focus is through real-world business examples, and we're beginning to see more of them.Cloud storage startup Nirvanix, founded last year, is offering details on how its storage delivery network is being used by independent film studio Doom to serve video trailers and other content associated with its new flick "On The Doll," a movie about the victims of child abuse.

Nirvanix's SDN is a distributed cluster of storage nodes running the company's Internet Media File System. The main benefit of storing content there is cost savings -- $500 per month compared with as much as $15,000 per month on a content distribution network -- according to Thomas Mignone, director and writer of "On The Doll." That discount, however, comes with a trade-off. Nirvanix's SDN isn't ideal for high-volume scenarios where millions of users are trying to download the content.

In another example, ice cream maker Haagen-Dazs' franchise operation is talking about how it's using Force.com, Salesforce.com's "platform-as-a-service," to extend the functionality of Salesforce's CRM applications. As my colleague Mary Hayes Weier writes, the business is using Force.com to track franchise store openings, remodel dates, inspection results, and the training of new shop owners. As a small business, it needed the help of a software consulting firm do the fine-tuning. For more, see "Salesforce.com Touts Haagen-Dazs As Cloud Customer."

And finally, InformationWeek's Nick Hoover reports that Chiquita Brands International -- a marquee customer of Workday's HR-as-a-service applications -- is using remotely managed, on-premises e-mail service from startup Azaleos rather than an e-mail service that's hosted "in the cloud."

Chiquita CIO Manjit Singh says hosted e-mail providers can't yet guarantee the uptime his business requires. Also, he's not convinced they'll be able to resolve e-discovery requests without added cost, he doesn't want sensitive e-mails stored outside Chiquita's data center, and he wants control over the software versions he runs and how patches get applied.

These on-the-street examples illustrate how cloud computing can provide new capabilities and increased flexibility without forcing businesses to invest in servers and software. They also reinforce the point that cloud computing isn't a solution to every problem and has its limitations.