Lee Drew had a chat with some cousins the other day. He was sitting in his home office in Orem, Utah. Four of the cousins were in England. One was in Australia, another in South Africa. A few more joined in from other parts of North America. Drew is one of a new breed of genealogists who are doing things that would have been impossible in the not-so-distant era of dusty archives and whirring microfilm readers. He has found so many of his relatives that he needs a computer database to keep track of them - all 1.7 million of them. Just as modern equipment has made it possible for any reasonably motivated person to climb Mount Everest or dive to the sunken ship Andrea Doria, new technologies have made it possible to achieve incredible genealogical feats with relatively modest effort. Now, it takes nothing more than casual curiosity and a few hours of research to discover that US civil rights activist Al Sharpton is descended from slaves who were owned by ancestors of the late South Carolina senator Strom Thurmond, a staunch opponent of desegregation That feat was accomplished by the commercial genealogy Web site ancestry.com, which boasts of having the largest on-line family history database in the world, with more than 4 billion records. Among the company's 725,000 subscribers there are people who have discovered they descend from royalty, or Mayflower passengers, or that Butch Cassidy is their seventh cousin. "It's a great time to be alive," Drew said. Internet genealogy can be extremely productive, agreed Dick Eastman, who writes an on-line genealogy newsletter. But it depends greatly on where your ancestors came from. The Internet is great for the United States, especially New England. And it's pretty good for Britain and Ireland. But if your ancestors came from Southern Europe, Africa, Asia or even Canada in some cases, the Internet can be pretty useless. "If I want to go look up my FrenchCanadian ancestors there's almost nothing to help me more than two or three generations back," Eastman said. "It's not going to be as rosy an experience as some of the on-line services would like you to think." Herbert Huebscher, a retired electrical engineer from Franklin Square, New York, found himself in that kind of situation when he went looking for his ancestors. The most distant ones he could identify were Ukrainian Jews who were living in small village near the Romanian border around 1830. "In general, Jewish paper trail genealogy tends to hit a brick wall around 1800, give or take 50 years," Huebscher said. To push further into the past, he turned to DNA. DNA testing has made it possible for people to make connections when the paper trail fades into tatters. The technology was used several years ago to show that Thomas Jefferson - or one of his male relatives - fathered a child by his slave Sally Hemings. It has also shown that a significant proportion of men in modern Ireland can trace a direct male descent from Niall of the Nine Hostages, a legendary 5th-century king. Customers of Relative Genetics, a company based in Salt Lake City, have traced their roots to Scotland, Africa and other distant countries with DNA testing. Huebscher had his own genetic profile tested by a Houston-based company called Family Tree DNA. He found that he matched one other individual in the company's database, a South Africanborn Londoner named Saul Isseroff. It turned out the two had some very distinctive anomalies in their DNA profiles, which allowed them to identify other matches as new Family Tree DNA customers joined the company's database. They have now found more than 40 closely matched families. Nearly all of the families were Jewish, and nearly all of them trace their heritage back to Eastern Europe - though oddly enough, one family traces its roots to Puerto Rico. A statistical analysis of the genetic data showed that whether they were named Huebscher or Isseroff, Wolinsky or Rosa, all of the families must have shared a single common ancestor who probably lived four or five centuries ago, long before most Jews even had surnames, much less written vital records. Though his research is not yet conclusive, Huebscher believes the common genetic ancestor may have been descended from Sephardic Jews who lived in Spain before the Inquisition. Just a little patience may be enough to solve the mystery, said Peggy Hayes of Relative Genetics. "The databases are growing very rapidly," she said. "As the genetic genealogy databases grow, the success rate is going to grow as well."