My first arduino project is to attempt to learn both arduino programming (seems dead simple to me so far) and android programming (the learning curve for android seems to go straight up then bend backwards to drop me on my head :-).
The ultimate goal is to produce an open source universal remote system that can fully exploit the potential which the annoying logitech harmony fails to achieve. (Think of this as something like the Logitech Harmony Link only without the 8 device limitation, dependence on annoying logitech setup software, or power sucking Wi-Fi interface.) I'm calling this the AardRemote project.
I just preordered a Nexus 7, and while it looks like a great tablet there is enormous disappointment that is doesn't have an SD card slot. Everyone wants more than 16Gb of space :-). Thinking about this, it occured to me: What if you combined a Teensy microcontroller board, a Micro SD Card Adapter, and a JY-MCU Bluetooth Module? (Total parts cost $32.60.)
You could power it from the Nexus' charger (assuming it is a standard 5 volt USB charger) and run the Nexus on batteries while transferring files, so no additional wall warts or batteries would be required.
All it needs is a load of microcode and a load of Android software to talk to the microcode. (Simple! :-). (And I haven't investigated, but existing bluetooth file transfer schemes might already be able to use RFCOMM, I see something called OBEX mentioned in the same title with RFCOMM in google searches, would need to read up on this more to know for sure). I doubt you could make it look like a mounted filesystem, but you could at least send and receive files to and from a micro SD card.
Of course, if this USB host API scheme works out, there will be no need for all this silly hardware :-).
My initial book scanner project has sort of languished. I never really figured out a good way to make a platen work and avoid major problems with reflections off the glass, and getting the SDM camera microcode to do what I wanted was also a big problem.
I've decided I like the idea of photographing books without a platen and mathematically flattening pages, and have vague plans for an arduino to control some LED lights and a laser pattern generator and interface it with the (not yet available) Polaroid SC1630 high resolution android powered camera. Of course, since this camera has almost totally disappeared from the Polaroid web site, I guess I'll have to wait for the rumored Samsung Android camera :-).