Creating and reading QR codes and 2D Codes

QR codes are something really useful but still not that popular since not all smartphones and camera phones include a code-reader app.

This is—almost—all you need to plunge into the QR Codes arena:

· ZXing Online Decoder, if you don't have a camera phone to begin with.
· Kaywa Code Generator to have some fun and amuse your friends or create these digital info capsules.
· 2D Sense is a nice—and free—iPhone app.

A sample below: