This is important stuff! CNNMoney.com recently put together a list of Web 2.0 companies that are emerging as the vanguard. Some of them I have heard of and even used; others are unfamiliar to me. They are grouped in categories: "Social Media," "Mashups and Filters," "The New Phone," "The Webtop," and "Under the Hood."
See: The Next Net 25: 25 startups that are reinventing the web (March 3, 2006)
Thanks to Marty for pointing this article out to me!