Tracking stock pedigree and automatic stock taking.
I was in charge of writing a prototype system in 2007ish of a system with NFC scanners that could be deployed to schools to track children and their healthy choices (checking out exercise equipment, checking it back in, buying healthy food from the canteen, etc). The NFC tokens would be combined with cleverly fabricated dongles to make them more inviting. I was a bit concerned about the privacy aspects as my bosses got really carried away (tracking how often children use the toilet, etc), but it never got past the prototype.
Among some of the research I did I thought that being able to track the pedigree of a single item from manufacture through warehouses, backdock and eventually on to shelves would be amazing - for everyone.
And whilst the item was on that shelf, if each shelf had a reader, then it would be possible to do automatic stock-take of what it was carrying and communicate the results to some centralised system.