I bought "Card Scan" a while back, went to a trade show and 350 cards after 4 days.... took me a couple of hours to scan `em all in and then you can correct any errors as it displays the image of the card too.
Not a perfect product as there are one or two things it gets wrong but overall easy to use and quick.
I also tried Card Scan a few years back and was actually fairly impressed at how well the OCR function worked. But, the last thing I needed was another application to use on a daily basis, so I exported the files into MS Outlook and ditched Card Scan.
Speaking of MS Outlook:
Craig, have you thought about using Outlook Contacts as your database? You could scan the business cards in as small JPEG files and then paste them into the "notes" area in Contacts. By doing this, you would have the contact info and the image of the business card displayed on the same screen.
I`m guessing that Outlook might get a little sluggish if you had several hundred graphic files but it might be worth a try.
Act by Sage, uses a card scanning system that integrates with there software. Hope that helps.