I commute, and road bike, on a flat bar. I have ergon grips (the cheapest models, w/o ends) and then some carbon fiber bar ends. like the above poster said, they're in an almost horizontal position, and I get a pretty nice aero position.

the bar ends are also nice for all the climbing where I live. I'm currently in South Florida w/ that set-up, where I'm pretty sure it looks crazy. but so does the road triple, mountain rear cassette, and all that.