Web 2.0 is almost instantly associated with user-generated content. While Web 2.0 encompasses more than that, user-generated content is the first sign of a Web 2.0 site.

Even among the Web 2.0 sites some are more popular, some are less. Personally, I believe that one of the most successful directions is video sharing and streaming, with YouTube being a vivid example.

However, YouTube is a universal video sharing service. Almost all general markets are already taken by big players who have enjoyed the first mover advantage. But niche markets are still open and I believe that is where we will see the future Web 2.0 sites appearing in.

What will you get if you take baseball and add Web 2.0 to it? Yes, you'll get Actober.com. It was designed to promote the MLB 2007 postseason. The Actober.com site lets fans put together videos containing their favorite baseball moments. Fans can take the clips both from the site's archive and from personal clips. Users with the best videos can win tickets to the 2007 World Series.