Google's recent purchase of YouTube is a strong signal that video is the next big wave of content to hit the Web. Photos and other images are also becoming much more prevalent. This trend has developed in part because so many users now have the broadband connections necessary to receive and transmit multimedia files. The increase in online multimedia content means the types and amount of information users can find on the Internet is expanding rapidly. However, this information is largely useless unless it can be searched effectively and efficiently.