On the Egeniq blog today there's a new post from Ivo Jansch looking at QR tags, one of the new "hot" trends that're showing up everywhere from websites to magazines. This new article introduces you to them and gives a few examples of how they're being used.

In this post I'll try to look beyond the hype. After the peak of inflated expectations we will eventually get to the 'plateau of productivity', at which point QR tags will have become mainstream. This is the moment when marketeers stop talking about it and we simply use it as part of our applications (this is a good indicator – the same happened to terms such as ajax and web 2.0). I will discuss the three major ways QR tags are applied. I hope the analysis inspires people to come up with innovative applications of QR codes.

He breaks down the codes into different types - ones with human-readable information, those with structured, standardized information (ex. a vCard with personal information) and a code with application specific information. For this last type he gives the example of allowing it to authenticate users without the need for them to enter the usual username/password. If you're interested in how to create QR codes for your own applications, there's several PHP resources to help you get started.