Pentax just announced a GPS unit for there DSLRs. It looks big and bulky- probably because they power it with bulky AA batteries (why?). But it makes me wonder if we are trivializing the problem with integrating a GPS in a APS-C or larger camera. All GPS units do require an antenna and there is precious little room in all the cameras I can think of for an antenna- especially on top of the camera where buttons and prisms tend to be.