Jigsaw is a marketplace for contact information, and it is very efficient. If boasts detailed personal contact information for 2.5 million people, and 7,000 new people are added every day. If you want the name, title, email address, direct phone line and/or address of any executive of any company, there is a very good chance Jigsaw will already have it in its database and will sell it to you. And if you are a sales guy and have no ethical concerns about where you get your contact information, you probably already know all about Jigsaw.
More Evil Web 2.0
Brought to my attention from Tech Crunch, more of the Dark Side of Web 2.0.