Using Web 2.0

Obviously web 2.0 and all of its components can be useful when trying to get information out there. But in many cases, a critical mass is needed for something to be noticed and you can't create critical mass on your own.
In order for a blog to be noticed a lot, many people have to talk about it and link to it. Searching Technorati shows how difficult that can be. Yet, unusual things show up as bigger than they are.
Yahoo has a site called "Upcoming" where you can post an event and others can post if they are attending. The attendees can then post that they are attending other events and the first one gets posted as an "You might also like" event.
For instance this one http://upcoming.yahoo.com/event/185007/ about a charity screening of the movie Serenity has sushi making and Open Doors Toronto as similar events when they aren't at all. The only thing in common is the person attending.
It is, a little like browsing through the book truck of returns or someone's personal bookshelves.