You can use the Relations application as client for the Semantic Web.
You can drag a web page from your browser and drop it on an item in the Relations browser. The application, then, extracts the metadata contained in the web page.
You will be asked which type of item you want to create with the extracted data.
If you select Text, the application will create a text item of type 'Web-Page'. Thus, the extracted information is about the web page you dropped. However, if the web page contains bibliographical metadata and if the application knows how to extract this information, you'll get the additional choice to create a Text (Bibliography) item. In this case, the extracted information and the created item is about the bibliographical item contained in the web page you dropped.
Note 1: The Relations application can extract bibliographical information formatted in the COinS, unAPI or RDFa format.
Note 2: The drag and drop capability with web pages gives you the possibility to build up a bibliographical database using Relations without the need to enter every bibliography by hand. You just surfe the internet for the requested book or article and drop the web page you found to an itme on your Relations browser. Unfortunatley, the Relations application is not able to extract bibliographical information from the Amazon online catalog. However, you can use WorldCat (The World's Largest Library Catalog: www.worldcat.org) to look for bibliographies you can drop on your Relations browser.