Searching through the Google Directory
Google is a search engine, in fact, it displays the results without any particular classification. It is possible to use a directory made in Google:
http://directory.google.com/
Web sites referenced in this directory are selected by volunteers from the Open Directory Project (ODP), a worldwide presence. They are grouped into general categories, which were subdivided into sub-categories for more detail.
For full details on the proposed ODP, visit
http://www.dmoz.org/about.html
In this classification categories was associated with the Google search technology. It allows to organize the sites in order of importance, not alphabetically.
Tip: the most popular directory are displayed in bold.
Note: that the Google directory lists just over one and a half million URLs. We are therefore far from the eight billion web pages indexed by the engine.