On hundreds of Web sites worldwide, the messages are brief but poignant: "Missing: Christina Blomee in Khao Lak" or "Where are you?" Some are nothing more than names, ages, nationalities. Others list details of where loved ones were last seen. Some have pictures of the missing.

All convey the aching desperation of people from Italy to the United States seeking news about family or friends caught in the earthquake and tsunami waves that ravaged southern Asia.

Web sites and blogs have become the announcement boards and lost and founds for a disaster that has left many thousands of people unaccounted for, including 2,000 to 3,000 Americans and thousands more Europeans and other non-Asian visitors to the region.

On the British Broadcasting Corp.'s Web site, dozens of people posted notes seeking someone.

"Does anyone have news of my colleague Chuck Kearcik and his wife Melinda and children Candice and Charlie (US citizens working in Kuwait, vacationing in the Maldives)?" asked Andy of Kuwait City.

Cheryl Boehm of Houston searched for her father, Jesse L. Adams.

"He is an American citizen and is retired living on South Pattaya Beach. Please contact me with any information as I have no way to find or communicate with him right now! Please help me find my Dad!!"

Another, Jaclyn Higgs of California, pleaded for help in finding her family. "I am desperately trying to contact my four-year old son Aidan Ashburn-Higgs and his father Jeffrey Ashburn who both flew into Thailand on Sunday. I have not heard from them since they left the airport in San Francisco. If you see this, please let me know you are safe."

Others sent text messages from across continents in a bid to find those who are missing.

In Sweden and Denmark, mobile phone operators stopped charging for mobile calls to and from Southeast Asia for 48 hours to make it easier for survivors to get in touch with their families.

For people with a less personal interest, the Internet also provided images and news of the destruction, including firsthand accounts from bloggers who lived through the waves and quickly posted pictures and descriptions.

Some people turned to the Internet to raise money and awareness of the disaster.

Amazon.com is asking its users to make a donation for disaster relief through its Web site. America Online said it started a site for its members to make donations to relief agencies, and said the company itself had donated $200,000 through the American Red Cross.