I was recently introduced to the D2 barcode concept after getting an Android phone (HTC Evo) and love how convenient it is to use them to install software in Marketplace. I never noticed anyone using them when I was using the iPhone, but hopefully they'll become a universal way to input small amounts of data from computer to mobile phone.

Thanks for providing a free generator so I could test the concept and see how these things are created. I'm going to add a barcode to my business card, though I doubt too many people will ever scan it.