Sonesta International Hotel Co., for example, is made up of 34 hotels, resorts, casinos and cruise ships worldwide -- some of which the company owns directly, while others are managed or franchisee properties.

Each has its own infrastructure for guest services -- cable television, Internet access and the like -- separated for security reasons from room-reservation and facilities-management systems, says Carol Beggs, vice president of technology for the Boston-based company.

Tying them all together -- aside from data downloads from financial and room-reservation systems -- is e-mail. It's asynchronous and detached, but if it's reliable, it provides a high enough level of communication to coordinate even a global business, Beggs says.

One hitch for Sonesta's IT is that crunch times often conflict.

"Periods during the day where check in/check out is busy are different depending on where you are, and the seasons between facilities in the Northern Hemisphere and Southern Hemisphere are opposite," Beggs says. "So even when you can do a system update at the same time in two locations, we tend to work around when a particular hotel is busy."