Like a child progressing into adolescence, the Web has entered a new era of sophistication. We used to spend most of our time just surfing the Internet--reading and downloading whatever we could find. Nowadays we're more likely to create waves ourselves by sharing our opinions, photos, and home videos; collaborating by text, voice, and video; or adding our own data to maps that span the globe.
The shift from consumption to participation is a critical change in the Web's evolution. It's now easier than ever to post photos, documents, and other files to a blog, or to publish content as a news feed. Many sites permit us to add keywords, or "tags," to our photos, videos, links, and other shared resources. For example, you might add the tags "Barcelona" and "water balloons" to a photo of a soggy day in Spain. Tagged files can meld with similar content from other contributors. Tags also allow audiences--either public or private--to search, group, and otherwise slice and dice our contributions. Naturally, we can use the same tags to discover interesting, funny, or beautiful content we might not have unearthed using a standard search engine.
Here's a sampling of the most useful and interesting sites and services of what some call Web 2.0. All promise to deliver the best Internet experience yet. (Many of these are run by fledgling companies or by individuals, so surfer beware.)