Sounds interesting, though you'd probably need to do starmap recognition to know which way you're pointing (azimuth should be ok from the accelerometers, but depending on which way the compass is orientated (and assuming it has one) it might not work properly when held up like that).

In any case it sounds doable and pretty cool (assuming the camera is able to see at least some stars tpo do the direction matching, which depends on its internals)

There's already a star map app isn't there? I wonder how hard it would be to hack heading and azimuth input into (from compass, accelerometer, starmap watching, etc.) that....

Anyway, cool idea