If you ever need an example of the exponential rise of technology, look no further than the digital camera. The ability to capture images on an electronic sensor has transformed photography and the way we record life's precious moments (and plenty of the un-precious ones as well) in less than 25 years. So how will we capture our holiday snaps when another two decades have passed? By 2030, will today's spanking new DSLR be as unrecognizable as a box brownie is today?