RFID for conception

From the RFID journal, an interesting approach to using RFID enabled systems as data-loggers http://www.temperatureconcepts.com/ a UK-based company has a device that detects ovulation by logging armpit temperature and then downloading the data via RFID. What is interesting is that the RFID element is used as a communication channel, which is turned off most of the time, rather than a conventional zygbee or mobile phone type device. In some ways its not RFID at all, its just piggybacking on the fact that readers are cheap and RFID technology allows this sort of reader- powered data transmission to be implemented easily. The device is pretty expensive - 500 UKP but this is a nice market to be in and one could conceive (sorry) of models where people hire them or are lent them as part of a fertility programme.
The model of using RFID as a data transmission tool is certainly interesting, and it may be that there is a markte for "dumb" tags, "Smart" tags and communication tags too.