After being side swiped a few years ago, I now use a whole car lane as long as there are 2 or more lanes in the city. Between city blocks, I also move out of the lanes to let cars pass.

I have found that no matter how close I ride to the curb, there is not enough room for a car to safely pass without going into the next lane over, and many people don't understand how wide their cars really are. By riding too close to parked cars, I put myself in danger of getting doored.

The last few times I have ridden my bike in the city, I have had people honk at me and then deliberately pass me inches from their bumper. I normally just catch up with them at the next light and make them pass me again. These latest "brushes" have made me want to key a few cars, or at least make a bumper sticker saying I will.

What do others do when there aren't bike lanes?

I have found that leaving my left Wald folding basket unfolded helps. There are two ways to view how it works. The first is that it gives people a gauge to realize that the bicycle is wide. The second theory (my daughters) is that they are afraid that the basket will scratch their paint.

No matter how it works, I get more room with it unfolded. The second is that if I am really hugging the right people will pass closer than if they have to make a purposeful effort to pass. As such, as close as possible as you can get to the right will, counter intuitively, cause more close passes.

Like Robert, I try to extend the bike width visually. I always keep a pannier on the left side of my rear rack, then stuff a rain jacket or sweatshirt inside to expand it a little. Where I live, drivers tend to be cautious to a fault around bikers (think following and refusing to pass for block after block), but I figure it's a good idea to discourage close calls.

Best side-swiping prevention: Mount a fiberglass pole (on springs) with a sharp carborundum point so that it sticks out 3' from the side of your bike. You'll get plenty of room, and those who don't give it to you will get a nasty scratch on their paint. Through no fault of yours.