Web 2.0 applications
There are many examples of web 2.0 applications. If it is interactive, free, and uses new technologies then there is a good bet that it is web 2.0. Some examples include;
www.wikipedia.org. This site is an online encyclopedia. It is free for use for anyone who wants to. The content is also completely added by users in their spare time. If you know something to be true and it isn't on wikipedia already, then you can add a new entry and make the site that much better. They do have regulators who go through the site to make sure content is correct, but the true staffing is minimal.
www.youtube.com. This site allows video sharing. If your baby takes its first steps in Indiana, you can take the video, upload it on youtube, and your parents can see it in California on the same day. This is also competely free.
www.facebook.com. This is a social networking site. It allows for photo sharing, profile sharing, and an internetwork of people to keep in touch with. This is also a free utility created by college students.
These are all prime examples of Web 2.0 applications.