Yeah. And if you're going really slow (in a car) you're supposed to have your flashers on. Almost all slow moving vehicles (construction, garbage, plows, etc.) have flashing yellow lights.

I just think that flashing lights stand out in a city filled with all kinds of lights. Although, at night you need a steady front beam to lit your way. Plus some cyclists reported nausea from blinking front lights in the dark. I still use reflective elements though to make it more clear that I'm a cyclist.