please see first post for updated archive and added guide.
ref. OTG/host/usb stuff in general... the idea is cool enough but is it worth the effort? lots of software, etc. are needed and i think we can do more efficient. just modify my idea and add a bluetooth device instead of the sensor. then it would be truly wireless. i have already done something like this when i developed the "kindle touch personal weather station". i've hooked up a bluetooth module to "talk" to the kindle without wires - all for the sake of debugging. after i put everything together i just removed the bluetooth module and wired everything in side of the kindle. if it's of any interest i think i can put it all back together and publish it here. after all it was only a "serial bridge" using nothing but a bluetooth module...