NEW YORK — The disaster preparation plan at the Ralph Brennan Restaurant Group was two pages long in 2005, before Hurricane Katrina struck, and dealt mostly with how to use sandbags and plywood to protect a building. Now the New Orleans restaurant operator has a 68-page book that includes communications and technology plans.

Many small businesses have spent the past two years trying to make themselves less vulnerable to hurricanes and other disasters. Given the lessons of Katrina and also hurricanes Rita and Wilma the same year, many companies understand that planning needs to be more complex than once thought.

Charlee Williamson, the executive vice president of Ralph Brennan, recalled about the pre-Katrina disaster plan, "the first line of it said, 'there is a box of supplies in the closet.' The plan was essentially a plan to protect the physical plant of restaurants."

It included sandbagging and boarding up the windows of the three restaurants and for managers to take CDs with backed-up data home with them. "There was nothing in this two-page document that contemplated the tragedy of Katrina," Williamson said.

Two years later, the company's plan is considerably more comprehensive.

"First and foremost, there is an elaborate implementation schedule," Williamson said. "We count the days until a storm is projected to make landfall — when it's seven days out, we're watching that storm and we're starting to mobilize and get things ready."

With each day, there are steps to be taken. For example, if a projected landfall is four days away, "we start running down our inventory. We don't make any menu changes," Williamson said.

Like other New Orleans residents and businesses, William-son's company discovered that telecommunications systems in the 504 area code were so overloaded that communication was impossible during and after Katrina. Now, 10 of Ralph Brennan's top employees have cell phones from Idaho's 208 area code.

The company has also set up an online message board so employees can communicate, and there is a more comprehensive list of telephone contacts for everyone available online. The company's sensitive data, including documents such as insurance policies, have been electronically scanned and are now also accessible online.

Although many small-business owners have realized the need for disaster planning, there are still many others who don't, or who haven't gotten around to putting a plan together. Companies in areas vulnerable to hurricanes and tornadoes are often the ones that sense the greatest urgency about disaster planning, but all small businesses need to be prepared — fires, vandalism and power outages are other events that can shut down a business and even threaten its existence.

Small businesses just embarking on creating or improving disaster preparedness plans can find information on the Internet to help them determine what they need in a plan. A federal government Web site, Ready Business, can be found at www.ready.gov/business, and the U.S. Small Business Administration has its own site, www.sba.gov/beawareandprepare/business.html.

The Institute for Business & Home Safety Web site includes a section called Open for Business, at www.ibhs.org/business-protection, that includes the kind of things to consider in preparing for a disaster.

Thorp & Co., a Miami-based public relations firm, also had what now seems like a bare-bones disaster plan.

"We used to have a plan that mostly consisted of, 'Here's the call tree. Call the person above you and let them know you're OK or if you need help," founder Patricia Thorp said. But after Hurricane Wilma struck two years ago, "we've gone up a whole level in magnitude."

Thorp said that after the storm, she put a generator into the cottage behind her home and bought phones that don't need electricity to work — because cell phones weren't working after Wilma. She has also signed up with an online service that allows subscribers to access their PCs remotely, and all of the company's data, including client lists and contact numbers, is backed up with a company in Chicago.

If at least some of the employees are able to stay in town, "we could get through for days," she said.

Thorp has also been giving disaster prep items as holiday gifts to her staff: TVs that use batteries or can be charged in a car, heavy-duty lanterns and refrigerators that can plug into a car's electrical system.

"We've done a lot of work the last two years," she said. "We all take it much more seriously than we used to — we never had a hurricane before where you could just throw your cell phone away because it was unusable."