Web 2.0 includes web-based communities, hosted services, web applications, social-networking sites, video-sharing sites, blogs, etc. A Web 2.0 site allows its users to interact with other users or to change website content.
Many of these Web 2.0 services, to name a view;
…offer widgets, feeds and APIs for the easy integration into your website. Taking advantage of these services can radically enhance your website with very little capital outlay and will provide additional opportunities to drive visitors to your website.