Microsoft Tags are a method of communicating electronic information to mobile devices via physical printed or visual media such as print advertising, billboards, product packages, information signs, in-store merchandising, and video images. Basically you point your phone’s camera (with the tag reader application running) at a tag and the software instantly loads the information associated with that tag.

Originally, Microsoft Tags were a series of colored triangles in a square separated by white lines. The tag design has now been updated to only require colored dots, which can even be integrated into an image.

There’s even a Custom Tag Creation Contest, where the most creative tag concept wins.

For more information, see:

Microsoft Tag

Tag Update on Windows Mobile Blog

And to download the Microsoft Tag reader, point your phone’s web browser to: http://gettag.mobi