Use of brooms

[weirdsister06]

No: HPFGUIDX 94428

Does flying a broomstick involve the use of magic?  

Underage wizards are able to fly during school holidays without 
reprimand from the Improper Use of Magic Office.  Ron and his 
brothers practice quidditch, the little children flew mini-brooms 
during the Quidditch World Cup, and Harry escaped from Privet Dr on 
his broom in OotP.  If flying a broom does not involve magic, and 
the broom is merely a mode of transport like a portkey or floo 
powder, can muggles fly?  What if a muggle picked up a portkey or 
tried to use floo powder?