Griffin Technology: ClarifiI cannot resist. It's not on sale yet, but now I'm glad I haven't found a case I really like.
... Slide the Clarifi lens into place over the built-in lens of your iPhone.... ... With Clarifi's lens, your iPhone can image an entire business card with astounding clarity.... you can move in to 4 inches for crisp detail and great pictures.
And, of course, Clarifi is also a super-protective case, constructed of durable polycarbonate, with cutaways for access to power switch, headphone jack, volume controls, and dock connector. For use with Apple Universal Dock wells, Clarifi features Griffin's trademark EasyDock™ design: the bottom third of the case slides down and off to fit in standard dock wells.
Evernote will do offline OCR of scanned and uploaded images. I assume they do something special for business cards especially if you pay for their enhanced service. I assume an OCR app for the iPhone is on the way ...