Microsoft released new beta product which I think I saw on the Microsoft research home page for about one year or six months.
It is like bar code but version 2, with different colors and shapes where tag can be identified by for example mobile devices.
Physical media can be identified by and translated to live link for accessing information. Imagine printing color tag on your T-shirt with URL to you page, and when someone is using mobile device it can browse to tag defined URL and get necessary information. I have to buy some T-Shirt transfer paper now :).
More information can be found on http://www.microsoft.com/tag.
To download software for mobile device browse with you mobile device to this address: http://gettag.mobi/.
On my HTC mobile I was browsing to the mobile page using Opera Mobile Browser and when accessed page my mobile was recognized as an J2ME (Java 2 Micro Edition), nothing strange because Operas browser was an Java application.
No comment on that :).