One thought about A/C through a filament bulb. 60 cycles coming out of the wall works well, as our brains are not quick enough to pick it up, but a hub dynamo ain't gonna be making 60 cycles unless you are going ....... uhhhhh pi X uhhhh something x uhhhh....well, let's just say you gotta be going real fast. A friction sidewall powered one will spin pretty fast though.
My point is, you may look like a strobe light going down the road. This will probably annoy you and surely annoy the oncoming cager to the point of maybe aiming for you.
On the plus side there is some entertainment value in causing folks with epilepsy to go into a seizure and flop around on the ground. Not so much of course if that epileptic is driving the tahoe headed straight at you!
Perhaps I am completely wrong in this regard, but, I figured I'd throw my 2 cents in anyhow.
I think I am leaning heavily towards the dyno idea. Anybody out there got a dyno hubbed wheel they want to part with for a reasonable cost?