Tag-based indexing systems allow users to name web resources freely choosing keywords, called tags. Users (observers) may browse resources using a tag-cloud, a screen presentation that looks like an alphabetically ordered list of the most popular tags, visually weighted by font size. This project called Artsonomy, enables users to associate keywords (tags) to real artworks (for ex. in a museum) labeled with a QR Code by means of an application on a mobile device. The user's tags are collected in a tag-cloud on the Artsonomy website so enabling other obesrvers to share their experience after viewing an artwork.