I keep seeing "ghost cycles" around SE and NE Portland (old bikes painted white and put in certain locations as memorials to killed bikers, with signs saying "A cyclist was killed here", more info at OregonLive Bike Fun blog) I have mixed feelings about these. One the one hand, it's a good way to alert motorists AND bikers alike to be more alert and drive/pedal safely, but on the other hand, these seem like they may be a huge deterrant for new bikers. It's not exactly sending a great message to encourage more cycling in the city, when Portland has been rated the #1 cycling city in the US. I know it's not 100% safe to bike, but in general, it's still very easy and safe to cycle in Portland.