I've thought about getting one.. thing is, I have this habbit, that I've done since I first started riding on the street many, many years ago, of flashing the brake lights manually when I'm stopping or slowing down. It's just a natural reaction to hit the hand brake 4 or 5 times before holding it, and I don't even realize I'm doing it most of the time. If I got a flashing bulb, I'd probably keep up with my habbit and really confuse the poor bugger.
However, I would like to wire up the running lights to act as brake lights for additional visability. I notice that is how the local motorcycle cops have their bikes setup, complete with red rear running lights instead of amber. I had thought you had to have amber by law, but I guess if the cops have 'em, they gotta be legal

Cheers,
Brad