The World Wide Web can be accessed through a number of different devices, each having its own capabilities and limitations. Additionally, the content of the Web is increasing tremendously in size and variety. Yet, many devices do not embed support for all types of media and formats. Therefore, in order to provide as much information as possible to all kind of devices, media items have to be adapted. In this paper, we propose to adapt them by replacing incompatible media items by others found on the Web. The adapted media items must convey the same message as the original ones, while satisfying the target profile. We present a possible architecture to implement this and we show that search engines can already achieve this to a limited extent. Nonetheless, some results are unsatisfactory because media annotations lack semantics, are partial and are heterogeneous. Hence, we propose to use Semantic Web technologies, such as RDF descriptions, ontologies, ontology merging and matching, in order to select better alternatives, thus improving this adaptation framework.