That's why the old Union generator lamps throw such a nice beam - they've got the Fresnel-style lens.

I generally make up for the lack of a rear blinkie by using pedal reflectors and stategically placing reflective tape on various components such as the pedal cranks. These reflectors move and 'flash' as you ride, and attract attention in much the same way a blinkie does, but use free retro-reflective light and not batteries.