Germany
(last edit Feb 12, 2014)
Multicopters need to be lighter then 25kg. If it is heavier it needs a special permit. The usual rules like no flights over people, street etc apply. Every “commercial” flight needs pre ordered aproval from the local aviation authority. There is no global authority for the whole country.
Even within a single state ist possible to have different authorities. The flight request needs to include informations like a copy of a valid insurance, reason for flight, date, time and launch location etc. The local police should be informed prior the flight to avaoid problems. A official quick summary is available in German language.
BMVBS Kurzinformation unbemannte Luftfahrtsysteme
Great Site with lots of usefull information(German language)
http://www.mikrokopter.de/ucwiki/Aufstiegserlaubnis