I wouldn't have thought a front flasher was that useful in rural areas, but I had this happen to me twice in 2 weeks this year:

http://www.youtube.com/watch?v=UOwv_IXZdIk

I'm now running my front light in strobe mode. It's about 800 lumens and strobes about 8 times a second. It's highly irritating, but so is being hit head-on at 60 MPH. Nobody has pulled that on me since I started running that light - someone TRIED it just last night, but they pulled halfway out, saw me and dropped back in line.

If I wanted a light JUST for front flashing, I'd probably go for a 200ish lumen flashlight with a good strobe mode. It would be ideal to get a Dinotte amber front light but they're kind of expensive compared to a $20 flashlight (and honestly probably not significantly move visible). It'd be nice if other companies made amber blinkies, but they are super rare.