Ok, I have to add something.
For a long time, I've been told this myth from people locally about how it was "illegal to ride on the sidewalk". I had always believed, then one day I though "Hey, I should look it up". Turns out that where I live (Minnesota) - it's a bunch of crap. It's only illegal to bike on the sidewalk in front of a block comprised mostly of storefronts (where I wouldn't bike above 4mph anyways), and where clearly marked. Which is - only like 3% of all the sidewalks.
Perhaps there's somewhere it's true, but generally this "presumption" that it's illegal is way, way, way overblown.