Mobile Barcodes Technology

I have recently come across a new innovation. Individuals can create their own barcodes by visiting a website, and these can then be scanned using a mobile phone. I can see endless uses for this technology. For example, barcodes could be placed in advertisements (such as on London Underground) and scanned to access a website. They could be placed on business cards and in other marketing materials. I also have a few ideas how these could be used for the industry I work in, the travel and transport sector.