What is a Semacode?
Semacode is a trade name for machine-readable two-dimensional black and white symbols that act as "barcode URLs." It is primarily aimed at being used with cellular phones with cameras to quickly obtain a Web site address. The Semacode specification is open, and based on the ISO/IEC 16022 Data Matrix standard.
Semacode actually brings the world closer to machine readable tags that link physical objects to information on the internet via a cellular phone.
As the Semacode Website puts it: "A semacode is a small symbol that encodes a standard, web-oriented URL. The URL is embedded into a two-dimensional barcode along with error correction information. When the semacode reader software snaps the barcode, it launches the embedded URL on whatever web browser is available. By building on top of existing technologies, semacodes take advantage of work that has already been done without re-inventing the wheel. Semacodes use existing standards in symbols (barcodes), content-resource identification (URLs), and content presentation (web browsers). The blending of these technologies into the semacode gestalt allows any person with access to a computer to tag their local and urban environment, and anyone with a cellphone to read those tags and follow the virtual links."
The Semacode Website has free(for non commercial use) downloadable software: Reader, Server, SDK and Semamake Java Command Line Tool to create your own Semacode URL tags. They have detailed Technical Documentation and Development Guides as well as What Camera Phones Support This Technology.
Semacode really hits the mark because, as anyone who's tried knows -- typing anything -- let alone long strings of text, is difficult on cell phones. While "yahoo.com" might not be very painful, more complicated URLs ('while on the go') are out of the question.
Obvious applications include mass transit stop areas, telephone booths, hotel lobbies, restaurants, bars and clubs. If the technology remains 'open', you could post semacodes of your own in local newspapers, magazines and on your own business cards.
Depending on which web browser or micro/mini web browser you have, You might be able to view a regular HTML file via the Semacode URL... The Semacode Reader requires a cameraphone capable of pushing WAP text messages.