There are all manner of activities associated with USB drives--many of them useless--but the one thing that will always defy logic to us is their relationship with the sense of smell. The most recent case in point: The "Scent Drive."
Most such items try to pass themselves off as aromatherapy devices, sometimes combining their functions with other dubious features. But we're beginning to think they're actually targeted at people who are, to put it delicately, hygiene-challenged.
Think about it: Giving them a bar of deodorant soap might be a tad obvious, let alone offensive (even though they're the ones who did the offending first). Instead you can give them an innocent USB key with a surreptious dual purpose.