A Groupon affiliate last week did some offline promotions around Liverpool Street station by handing out USB cards that when plugged into the computer, loaded up the geo-targeted Groupon homepage via the affiliates tracked link.
Seems like a good idea! But it makes me think, what would make people go to the trouble of plugging in a USB stick instead of just typing Groupon into their web browser? Unless maybe there was a special discount that people could access via the USB stick.