Cycling on sidewalks feels safer, but it's actually more dangerous. [1] The problem is that cars don't expect something moving quickly on the sidewalk, and so hit cyclists at driveways and intersections.

[1] http://www.bicyclinglife.com/Library/riskfactors.htm

There are places that are shared pedestrian/bike paths. The east side of the GG Bridge when the west side is closed for instance. In those cases I think pedestrians should at least be aware of cyclists, instead of walking 4 abreast and blocking the entire way.

Yeah I had a bicycle guy quickly drive over the pedestrian crossing almost riding right in front of me.

I don't own a car and ride almost everywhere. In all the cities I've lived, my experience has been the exact opposite. Since the majority of accidents involve intersections, riding on the sidewalk doesn't do much other than put you in a less visible position, where drivers don't expect you to be and won't be looking for you.

Disagree. I cycle to/from work and to most errands here in Boston. The bike lanes suck in most places, but bikes on sidewalks are bad news.