http://www.princetontec.com/?q=eos-bike

I use one of these (EOS) for front nighttime flasher. Mine is actually a converted, original EOS headlamp from the early 2000s with a homemade mount to the fork crown fender hole. In my case, the EOS was "re-cycled" from retired backpacking duty after it was obsoleted by a much brighter Petzl headlamp. The current EOS is probably twice as bright as mine.

For daylight I run a Magicshine 900 bike-specific headlamp in flash mode. The EOS (or current EOS2) is inadequate for daylight duty, IMO. It's very hard to compete with full sunlight, and actually get motorists' attention. I've had drivers nearly run me over (they were driving on wrong side) staring down a flashing Magicshine, they hardly even noticed it, or me.

So, don't expect a relatively low output white flasher like an EOS2 to get you noticed during the day, or when riding in brightly-lit, high traffic areas at night. However, they are quite noticeable on rural roads, or other low-light areas.