Electric bikes are legal in my city, and I see them all the time. Not really a big deal, but great for older folks or people pulling large loads on their cargo bikes/up hills.
We even have a bike shop dedicated to selling them:
http://ebikestore.com/
like this guy (more of a city bike):
image courtesy ofhttp://pdxebiker.blogspot.com/
FYI, they are speed & power limited, so you can't really go that fast. And you have to pedal them.
Also, you guys don't have moped gangs in your cities like mine??? Whats that about???
image courtesy oregonlive.com