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.

Mr. 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 — 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 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 civil rights activist Al Sharpton is descended from slaves who were owned by ancestors of a late South Carolina senator, Strom Thurmond, who was a staunch opponent of desegregation.

That feat was accomplished by the commercial genealogy Web site ancestry.com, which boasts of having the largest online 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,” Mr. Drew said.

It isn’t just the databases. Mr. Drew also uses the Internet to communicate with relatives around the globe, sharing information and research tips. And services like Google Books give him free access to formidable university library collections.

At 57, he remembers the old days, when doing genealogy meant driving up to the Mormon church’s Family History Library in Salt Lake City or spending his vacations strolling through English churchyards looking at headstones. Now, it can mean nothing more than strolling into his home office and booting up his computer.

Internet genealogy can be extremely productive, agreed Dick Eastman, who writes an online genealogy newsletter. But it depends greatly on where your ancestors came from.

The Internet is great for America, 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 French-Canadian ancestors, there’s almost nothing to help me more than two or three generations back,” Mr. Eastman said.