QR code (http://en.wikipedia.org/wiki/QR_Code) is a 2D bar code used to encode fair amount of data in a sort of 2D bar code. This code can then be read by cell phones or barcode readers. My choice is for QR Code as it is one of the most used and a simple encoder / decoder for PC and mobile phones is readily available for free.
Another code is Data Matrix (http://en.wikipedia.org/wiki/Data_Matrix) which is now having some backup from both the US Govt and the electronic industry which is planning to add extra information on top of chips and small components: these would be read by automatic assembly machines for a more reliable and foolproof assembly of boards.
PC and mobile phones encoders/decoders are available for Datamatrix as well, but I went for QR code and basta ! No, actually I tried some free Datamatrix decoders and proved less reliable, on my phone at lest, than the QR decoder I am showing here.
"QR Code is trademarked by Denso Wave, inc. as stated in Denso Wave's" this is what can be read on Wikipedia and on Denso Wave's homesite but we can read also that (http://www.denso-wave.com/qrcode/microqr-e.html) "QR Code is open in the sense that the specification of QR Code is disclosed and that the patent right owned by Denso Wave is not exercised.".
And that's great because this opens to a great deal of opportunities.
...Follow me then and you'll have Y2010 business cards also.
Note (01/02/08) :
Jaxo System's web address has moved to http://www.jaxo-systems.com
(thank you, jackOjack)