Here's my really really ugly setup. But I guarantee you it works. And I've run it by several cops and they all give it the thumbs up as well.

This won't work for most of you, but if have a rear rack you can take a Dinottee light head and strap it to a piece of hose or PVC tubing and point it at a reflector, but facing forward. Set the light to strobe and you are now "noticed from all directions.
The light bounces off the reflector, and since it is behind you it doesn't blind oncoming motorists. There is so much "over-flash and spill it is impossible for people not to see you from all but "head on" - and probably that too! (this is a flash photo - the light would have been brighter) Tail lights just above reflector, under seat