At FTF (Freescale Technology Forum) in 2011 at least (didn't go this year), used them on everyone's name tags and booths, so rather than passing out business cards, you used the iPod to scan them and it would send you a nicely formatted email along with the contacts for easy importing into whatever contacts you used. It was about the only time I felt they were done right.

And if you scanned the codes that were given in the different tracts, you were also sent the PDFs and slides of that tract.