We have covered embedding links to social networking sites and more interactive elements in your website, including the following:
Videos from YouTube, Google Video, and other popular video sharing websites
Twitter feeds
Social bookmarks
Although adding these more interactive features to your wiki can be a good thing, remember that they should only be used to enhance your wiki, and not as its primary focus. Without useful content, your wiki's visitors will leave your wiki and not add anything to the community that you are trying to create.