I've never come across anything like that, but if you have a scanner, OCR software (typically comes with scanners) - then you should be almost set, you'll just have to do the whole process manually.
I'd recommend putting a card in the same place in the scanner, probably one of the 4 corners, running a scan, saving the image, then running ocr on it and copy/paste the data into whatever contact management software you have. Kind of a hassle, but you wanted to avoid another gadget ;)
Alternatively, you could use my online software, Record Sage, to accomplish it with a little more ease, although it's not exactly the same as above. Record Sage (www.recordsage.com) allows you to keep track of lists of things... with 'things' being anything you want, including business cards. In fact there's a special feature specifically for business cards. You scan the card and enter an Item (see the site for details) and indicate the image to use. You have a number of other fields, including free-form description, that you can use to add any text details you'd like. Then you run the Business Cards Report and all of your cards are neatly shown, broken down by categories, as if looking at pages of cards. Each image can be clicked on to view a larger version and of course anything could be printed if needed. I recommend scanning with final resolution being 640x480 (must be less than 50k image), then everything is nice & uniform. There are many other features to Record Sage, although all use the same simple interface. You can check it out for free.