Panarea island is a motor free island!
Every year is issued a law that limit the access to the island for motor vehicles (motorcycle too).
In 2005 the time period has been from 1st May to 31st October.
Note that also the Police car is an electric golf car.
The limit does not worth much, if you think that are less then 5km of paved road.
From Sicily you can get to Panarea by boat either from Messina or Milazzo. The price was around 20 euros and it took some (4?)hours to get there.
Also, be aware that (especially in September) the boats stops operating if the weather is bad; too windy, thunderstorm.
Check out the internet page for details.