Oh...i dont know if i like the idea about a film about Prince Harry, and why is it called The Spare?!

IT's a bit of an odd choice, although I do like Harry I don't know if I'd find it an interesting film. My suggestion would be Rupert Grint or Jamie Bell, just because

Jamie Bell... oh yes, I do like that. Maybe I could imagine Rupert Grint playing the part, too. And Seth Green as Prince Harry would be pretty interesting to say the least. But like the previous posters, I'm not really sure if I'd find it an interesting enough film.

i think it's called the spare because he's second in line after prince william to be king, and third if you count their dad.

It's known as "heir and spare" - Royal couples (those in DIRECT line to succession of the throne) were supposed to have more than 1 child in case something went wrong. For example, first child born : a girl, can't take the throne & so in a family of 3 children with the last being a boy - HE ascends to the throne due to gender. Next, the children NEVER make public appearances together or travel together in case something happens... Accident, kidnapping attempt, etc. While Princess Diana was alive & still married to Prince Charles she insisted on taking BOTH her sons with her wherever she went... earning her some chastisement from the Queen.
-
It's complicated, to say the least, & would take a long time to explain everything... so read up on monarchies. I'll help by posting this link:
http://en.wikipedia.org/wiki/Elizabeth_II_of_the_United_Kingdom

how about Robert.....
his my Prince charming....lol