I honestly hate the OTG cables, since I hate to have that "tail" on my Nexus 7, however they are so inexpensive that it is hard not to use them.
I wonder, would it be any interest on a device like that? my goal is to gather enough people to build close to 1000 units so that the price is reasonable.
I already got the design done, and a prototype build, so I am going around asking anywhere i can to collect opinions to see if this is something that could spark any interest.
Project is at Indiegogo com - just search for "microsd"