Waaaaaay back in 1984 I was in the UK and saw tons of reflective paddles that stuck out to the traffic-side of a bike, wider than the handlebar ends. These were on the seat post.

Anyway, they really emphasized the size and width of the rider, as opposed to just the width of the bike.

They were pretty cool, and seemed to work well. I'd love to see some of those around here. Guess I'd better go play on Google for a bit.