Kevin Ham, profiled in the Business 2.0 article (dated May 22, 2007) referenced below, was trained as a Doctor at the University of British Columbia. He is considered to be “the top player” in the industry. He owns “300,000 domains which generate about $70 million in revenue annually” (combined with a few other ventures) . His sites receive 30 million unique visitors a month. Agoga.com, one of the main sites, receives about 8 million unique visitors a month. His portfolio is estimated to be worth $300 million.

His start: one of the first to write software that let him try the domains on a free trial
at the beginning: created an online directory of Web hosting providers called Hostglobal.com (around 1998)
six months after Hostglobal.com was launched, he was earning $10,000/month in advertising sales
one of his advertisers who was generating 15% of the revenue, a domain registration service convinced him he would get into that too
started a second Web hosting providers online directory called DNXindex.com which gave customers a way of registering domain names
with DNXindex.com, he provided weekly lists of available names using free sources on the Internet and charged anything from $0 to $50 building up a customer base of 5000 within 2 months
by June 2000, he was making $40,000 a month
then recognized how to exploit dropped domain names: learned about the master list of all registered names at the time, a list published by Network Solutions called the “root zone” file (now owned by VeriSign); names that disappeared, he thought, were being placed “on hold” and then would drop to the public 5 or 6 days later & he would attack them
struck deals with several discount registrars writing them software to guarantee they would capture the names Ham would buy through them in late 2000; in a 6 month period, he registered more than 10,000 much to the disdain of his competitors
in 2004, took all his domains from 3rd party registrars and launched his own registration service creating the company Hitfarm which did “a better job of matching ads with domain names” for himself and 100 other domainers
the man behind the scheme of mistakenly typing the domain name like ‘.cm’ instead of ‘.com’ (.cm is the domain suffix of the West African country of Cameroon) - this process is spelled out in a patent application filed by Seeman (business partner below)
currently working on .co (Columbia), .om (Oman), .ne (Niger), and .et (Ethiopia)
focusing currently (2007) on a new company called “Reinvent Technology” which builds Internet Businesses around his domain names
uses yahoo.com (overture) for his online advertising instead of google adwords
owns God.com, Satan.com, Weddingshoes.com (worth $9100/yr), Hoteldeals.com (paid $171,250 for it), FruitGiftBaskets.com (paid $26,250 4it), Religion.com (leased an entire 27th floor, hiring 150 engineers, salespeople & editorial folks to support this venture which will focus more on “meaning” and less on keywords)
knowns how to code in Perl
business partner Colin Yu, business partner Robert Seeman (behind .cm & chief adviser at Reinvent Technology), domainer partner Steven Sacks
Other Individuals:

Amy Schrier, sold Blue.com in March 2006 for $500,000.00 [2]

Craig Lovik began exploiting the generic typo in 1998. No he owns 200,000 names, including lucrative misspellings like peircings.com and Pheonix.com

Frank Schilling made his mark buying generic .com names in 2002 and 2003, when others were fleeing the Internet. Today his portfolio of 320,000 domains is among the world’s biggest, and he works out of his home in the Cayman Islands. His portfolio is estimated to be worth $20 million. Represented by Atty. Berryhill (listed below)

Garry Chernoff bought his first domain Netincome.com in 1995. By 1999, he’d quit his job as a hospital electrician, and now lives on a 10-acre lakefront spread in B.C.

Gary Kremen, sold Sex.com to Escom, an adult-entertainment company, for $12 million. [2]

Ken Carey, a longtime autoworker in Grand Rapids, MI, and a part-time inventor owns 200 names including LowCostImports.com[2]

Rick Schwartz, a.k.a. the “Domain King” runs the T.R.A.F.F.I.C. conference annually.
His portfolio includes HotDates.com, Property.com (cost him $750,000 in 2005), Candy.com and Widgets.com. He sold Men.com in late 2003 for $1.3 million. He originally purchased the domain for $15,000 in 1997.

Scott Day, a watermelon farmer from Waurika, OK, discovered domain names in 1997 when he bought watermelons.com for $3000. Today, he holds one of the most admired portfolios in the business

Steven Sacks, domainer based in Indianapolis - works for Kevin Ham

Yun Ye was among the first to write code to automate domain purchases. In 2004 he sold his portfolio of 100,000 names to Seattle-based Marchex for $164 million.

Corporations:

Bob Davis, Managing General Partner at Highland Capital Partners which spent $20 million on YesDirect, a holding company with 600,000 domain names. YesDirect is developing content using those names according to Davis. [2]

Bob Martin, President of Internet REIT (iREIT), a domain investment firm that has raised $125 million from private investors including Maveron, the venture firm backed by Howard Shultz (Starbucks founder).

Lawrence Fischer, vice president of business development for SmartName.com which owns thousands of domain names like Stockquotes.com.

Vendors:

John Berryhill, a top domain attorney sounds like an ass in the article[1]

sources:
1. http://money.cnn.com/magazines/business2/business2_archive/2007/06/01/100050989/index.htm
2. http://www.usatoday.com/tech/news/2006-05-09-domainers_x.htm?POE=TECISVA