I've already seen the reflecting off of the signs with the other flashing lights I've used.

I'm only using the streets, if I go on a path I'd move to a steady light. It'd be interesting to see if any cars do pull over (I doubt it) when I use the flash.

Interestingly, when I used my previous "big" light (a 10 watt BLT) a co-worker said when he saw me from a distance, he thought I was on a motorcycle.

I'm not sure if being mistaken for a motorcycle is good or not. Do motorists give cyclists wider berths or do they dismiss them as no threat?