I have a notorious lead foot. I'm working on it. (I tend to be extra-extra cautious on the two wheelers, though.)
Now here's where I get all smarty-pants: Moped is not a brand name. It is a term that comes from "motor velocipede," and is used to describe a class of motorized bicycles which operate at less than 35 mph, thereby requiring no registration, tag, or specific license outside of a valid learner's permit. A moped can literally be a bicycle with an engine on up to a low-powered scooter or motorcycle.
"Scooter" is more difficult to define. Scooters can fall in the moped class, like the Metro you showed us on another thread, but there are large scooters which require the same license as a motorcycle. My scooter has a 125cc engine, and can do 50-70 easily on a flat stretch. Many companies manufacture scooters with large engines (250cc or more) which are capable of keeping up with a motorcycle.
The primary difference is the transmission. Scooters typically have a v-belt transmission. It's kind of like a jet ski; you just twist and it goes. No clutch, no gear-changing. This means that the brakes are also different than a motorcycle. You have two hand brakes. Your feet have no responsibilites whatsoever.
(I know all this because I get really peevish when someone refers to my scooter as a "moped...")
OH SNAP!!!!!

there us a fine line between scooter and moped as mentioned by you SJ and NH..... it is quite discombobulating here in Ok.
...how 'bout dem Rangers? That looked like a football score! I sure hope that's not all the bat they've got this year! 