Patmark PC software can automatically generate QR codes and Data Matrix codes.
Just type in the text/data you want to be stored in the code and hit start!
With marking QR codes, it is important to note that reading codes rely on the contrast between "dot" and space - on rough and/or dirty surfaces this is very hard to achieve - therefore it is recommended only marking codes onto finished surfaces.
Here is a demonstration of QR code marking.
