I just came across an article about Quick Response (QR) Codes which is a bar code that can be read by mobile phones and can be used to encode all sorts of information, such as URLs, contact information, location data, text, etc. Due to their matrix structre, these two-dimensional codes hold much more data than the more common one-dimensional bar codes.
You can generate QR Codes for your own Web site, email address or telephone number at Kaywa. Once the data has been entered and the code generated, the code image can be scanned from the computer display and the mobile device can then immediately connect with the encoded information. Smartphones such as iPhone, Symbian and Android have softwares that can read these codes.
Here is the QR Code for this blog post.