ZXing QR Code Generator

Those blocky QR (Quick Response) codes can encode more than just a web URL and the most useful one (IMHO) is for contact information.  Instead of handing out a business card that has to be manually entered (and usually isn't), they can simply scan it and add it to their contacts.  My favorite online QR generator is ZXing, short for "zebra crossing", which can encode nine different types of information.  Add that to the back of your next business card.

https://zxing.appspot.com/generator