I usually use my 400 lumen Cygolite in flashing mode, but it is an $80 light that I bought mainly for night riding. I also have a couple of these:


http://dx.com/p/3-mode-5-led-white-r...3-x-aaa-114064


It is a very bright be-seen light. When I stand a few yards back and look at it, it is highly visible. Under $5 shipped from china. I'm sure you can get them from a US source faster and for just a little more. I keep one on my beater bike for running daytime errands. I don't know how reliable it ultimately will turn out to be, but sofar, it works just fine and I've had them over a year.