Great idea but not really that feasible with the logistics and architecture to be put in place for acceptance (at an early stage of course if idea takes off). But seems ironic we are try to rid the world of physical cash in our communities - but yet adding plastic cards, be it all very clever they are too. Saying that, it is a good look upon the general uptake and adoption of Bitcoin, and maybe some of these cards will find their way into the hands of new people, who have only maybe heard about this magic internet money.. One question is, say if I have a 0.01 Bitcoin card gifted to me; I then go on to buy a coffee at the local coffee house, where does the change go?