Semapedia looks pretty cool. The idea is to attach Wikipedia “links” to real-world objects, e.g. famous buildings.
At the web site, you can print out a sheet of paper with a barcode-like encoding of a Wikipedia link which you can then attach to the real-world object. Other folks can then point their mobile phone camera to the barcode. A special software on the phone decodes it and fetches the Wikipedia page.
That’s still a bit convoluted, and the need for special software makes it impractical. But if mobile device manufacturers would standardize on a technology that can encode any kind of URL, not just Wikipedia articles, and include the decoding software in all devices …
(Phone network operators should like this because it would increase internet-over-phone usage, making money for them. I sense a business idea here. I’m sure there are at least ten startups working on this already …)
(via Information Aesthetics; Leo blogged this too last year)