The difference between "abracadabra" and "avadakedavra" is: "abracadabra" means "i will create as i speak", and "avadakedavra" means "i will destroy as i speak". suprisingly interesting yet useless piece of info. LOL!!
Oliver and James Phelps... Truly are Fred and George! James said in an interview that they did it at one rehearsal, but it kinda snowballed from there and they did it for a load of the scenes, then they got caught and had to re-shoot half of the movie! HI-LARIOUS!!