What's that up there, on top of that Nikon D90? It's a $39 hotshoe-based smartphone mount for DSLRs called the Flash Dock. While it looks like it's designed to take an iPhone an use it as an adjustable, makeshift speedlight, it's actually just a dock that holds your smartphone — no more, no less. The idea is that it'll make it convenient to use some photographer-friendly apps, like light meters, levels, depth-of-field calculators, and voice recorders while shooting. Still, sticking your phone to the top of your camera is only a bit better than holding the phone in your hand when you need it, and all DSLRs have light meters and (most) have levels, too.