Microsoft released their version of a 2D bar code reader this week at CES.
The MS code looks very similar to a QR code, but the color MS code can hold much more data.
It keeps getting hype as an iPhone app, but I downloaded the Windows Mobile software and it works great. It's much lighter than the QR code reader i-nigma.
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This article explains it well.
This link contains a good video about the tags.
The Microsoft Demo/Download page is http://www.microsoft.com/tag/
Is it practical? I'm not sure. Japan has been using QR codes for years. The same QR technology has been available in the US for a while, but never seemed to gain traction.
Do you think this will catch on?