Anybody know of any good ways to make a good high pitched sort of droning violin/mandolin sounds on an electric guitar? Settings, effects, techniques?

Examples include:
Arcade Fire, Intervention

Radiohead, Exit Music
Check out the studio version about 2:50 in.
Quote by frozenboogerman
using a violin bow works wonder

That would be awesome, but I've heard its hella difficult and gets rosin all over your guitar.