There's hardly any need to beat the why-no-photography drum in art museums anymore. Slowly but surely they're accepting the inevitable and releasing their collections to snap-happy visitors. In places like the Dowse there's still the familiar camera shape there in the dos and don’ts signage but now it’s as a do, as in, do feel free to take a photo.
A bit late to the game is this…er…game. It’s a two-player (you can be either a photographer or a security guard) that let’s you outwit guards as you snap stuff you're not supposed to. And yes ,you can use your flash to blind the guard for a quick getaway. It’s not quite on the market but if you like reading lots of instructions, you can see how it works here.