Absolutely! - up here in WA state our bicycle laws are written so that we are allowed to use whatever portion of the lane we need to for safety. I don't deliberatly try to antagonize motorists by always riding in the middle of the lane, but there are places - narrow single lane roads, bridges, etc. that I feel my safety is much more important than some car being delayed by 30 sec. so I take enough of the lane that if a car wants around it has to go into the opposing lane. People will try to squeak by you if you give them the room, but something makes them go all the way over if they have to cross the center line for the most part.

At least 4 of my team mates haved been hit by cars this spring by people either pulling around and turning right or pulling out of a side street and claiming that they did not see the person (our kits have a large bright chartruse stipe on them - they are hard to miss even from a distance). Personally I feel that it is better to be a somewhat aggressive with traffic even if there are drivers who are miffed at the delay. I don't ride in the "door zone" of parked cars, I take the lane if I feel it would be dangerous (to me) for cars to pass me or if I am doing the speed limit / speed of traffic. I act like a car at traffic signals - I do things like using left hand turn lanes, taking my proper turn at 4 way stops. Sure some people don't like it - got honked and yelled at the other day by some bozo who wanted me to weave in and out of the parked cars so that he could pass, but more people than not are if not considerate, at least neutral.