One of the fastest, easiest, and most powerful ways to organize content is to use tags. Tags are short, descriptive words or phrases that classify and organize wiki pages, blog posts, or mailing list entries.
There are two types of tags: content tags and meta-information tags.
Content tags describe what a page is about. For example, if you have a department wiki where everyone has a page describing himself or herself, those pages should be tagged with "bio." If you do a tag-based search for "bio," you'd find all bio pages for everyone in the department. Similarly, if you had a project named "ProjectX," you could tag all pages about ProjectX with the "ProjectX" tag.
Meta-information tags describe the page itself. For example, you could mark all important pages with "hot" and all pages that require review with "review." This way you can quickly find pages that are important or require review.
There are advantages to using tags:
Searching text can produce results that happen to mention what you're searching for but aren't necessarily about what you're looking for. With tags, you'd tag only pages for a specific subject.
You can combine tags to find exactly what you're looking for. For example if you're working on ProjectX and need to know everything important about it, you can do a search for the "ProjectX" and "hot" tags. Similarly, to find out everything in ProjectX that needed review, you'd search for the "ProjectX" and "review" tags. To find everything that's related to ProjectX, is important, and needs review, then you'd search for all three tags.
You can turn a tag-based search into a very effective Really Simple Syndication (RSS) feed. When you subscribe to an RSS feed through an RSS browser such as Mail, you're notified when a page in that feed is updated. If you subscribe to an RSS feed of the "ProjectX" tag, you're notified when a page related to ProjectX is created or changed.