There’s a new iOs app that brings the DVR/Tivo-like ability to skip back in time to your actual, real life. It’s called Hear (free) and it's (depending on how you look at it) either really interesting or incredibly creepy. Here's how it works: when you open the app, it automatically starts recording the sounds around you (at least within earshot) and stores that data in your phone for up to 5 minutes. If something cool occurs that you’d like to save (like a child’s first words or someone cracks a really funny joke), simply tap a giant button in the middle of the screen. This could also come in very handy during any argument.
Down Now: Here (free, iOS only)