Perhaps it is useless, but it's kinda neat, and more important is the fact that it's becoming more popular. Like someone else mentioned, having the barcode on say a business card makes it easy to import the contact.
Being in the advertising industry, i see HUGE potential for this. If I'm making an ad for a magazine, newspaper, or even internet (i scanned Darla's with my phone, so it works over a monitor) then I can put this on there, it takes up VERY little space, and provides more information to my consumer. I can also put a code in there, or a link that can only be found through that barcode, and I now have a database of interested people, cause I'd know that to get to that webpage, you'd have to have scanned my barcode.
We're obviously not there yet, but the more phones get a barcode reader like this, then the consumer education process can start, and then it's a HUGE tool for marketers.
However, for the here and now, and probably at least the next 2-3 years, I'll agree 100%, it's a pretty useless, but nifty app.