Can I take a photo of your business card?
I'm not sure why, but beaming business cards between PDAs never caught on as much as I would have liked. Of course Palm and Wince PDAs don't speak the same beaming language (of course) and I never saw it much in Windows anyway.
With my new fancy scanner, I can scan a stack of 60 business cards in a minute, so it's not going to take me long to do the physical scanning. Business card scanning has been around for a while, but it still presents challenges.
People like to do funny things on their cards. They put stuff on the back (not just for foreign language contacts, where it makes sense.) They put in coloured backgrounds and pictures to make the OCR process as hard as possible. They like to do embossing, or even strange shapes. (Some people used to put rolodex tabs on their cards to make them stand out in a rolodex.) They will put lines or other OCR killers in the background too. People should start expecting their card will be scanned and OCRd, and design accordingly. That means if you put in your stylized logo, but the company name in in plain text too. (Though the need for a URL on a card helps this nowadays.)
Of course, even better to solve the OCR problem would be to put just one string in a clear, easy-to OCR format, which is the URL of a vcard. Then it doesn't matter if I can't OCR anything else, I can get reliable (and up to date) information from there. (One could also imagine a hosting service with a standard URL prefix to put in front of a vcard ID so you don't have to take up that much room on your card. Another idea would be to standardize the VCARD URL so that it says something like "VCARD: S/xxxxx" where xxxxx is a semi-private string, and "S" means use the web URL found elsewhere on the card, with "std-vcard/xxxxx" appended to it. This way you don't have to duplicate the domain name, but nor can vcards be harvested. Otherwise we could just use the E-mail to extract the vcard.)
Anyway, I came up with another idea I will try instead of beaming. "Can I take a picture of your card?" Since I plan to scan people's cards anyway, why not save the trouble and use a small pocket camera I am carrying, and take a photo right there. You don't even have to give me the card. Will I be rude if I don't take the physical card?
Now admittedly, camera phone pictures may suck, and for this you really need a camera with a macro mode. On camera flash may present a giant glare spot unless you learn how to do it right, or are shooting in bright light without flash. The photo won't be nearly as good as a scan, of course. (I suppose one could imagine putting a 2" long hand-scanner line on the side of your PDA to hand scan cards, bar codes and many other things.)
The bad news is that cell phone cameras probably can't make the cut. They don't have macro mode, and if they have a flash, it's going to be very hard to get a good exposure on the card. You have to tweak what you can tweak and even then it may not be possible. (I found I had to use my cell camera's exposure compensation to drop it by 2 stops to avoid having the LED that counts for a flash not wash out the card, and even then it wasn't very good.)