Before there was random access memory, there was delay line memory. It was random in a different sense; it involved turning electrical pulses into sound waves, sending them through long tubes of mercury, and re-electrifying them at the other end.
Imagine a format that lies somewhere between photos and video, and a device that takes that format automatically, without you having to click a button. Microsoft’s SenseCam is a prototype that hangs around your neck, lifecasting everything you see.
It seems like something out of a movie (and hey, it is), but there’s some scientific evidence that we actually carry the memories of our ancestors with us in our genetic code. Apologies in advance to my hypothetical descendants.