Tagging the world

Collaborative applications such as Wikipedia are widely used nowadays, but Semapedia takes this one step further by letting you create physical hyperlinks to articles on Wikipedia and other offerings from Wikimedia in the form of 2D barcodes you can attach to any physical object. Users with a datamatrix reader installed on their cellphones can then read the linked article on the spot by pointing to an object with a 2D barcode. While there's an associated Weblog as well as a Wiki to get you started, more details can also be found here and there.