Below are some of the audition scripts some of the actors used. They reveal much about what was originally intended for some of the characters (including Arwen at Helms Deep!)
Note: these actually are genuine TORn was asked to take them off after they released a copy many years ago!

c h a r a c t e r s

Arwen and Aragorn's meeting
Aragorn and Legolas
Arwen at Helms Deep
Bilbo and Gandalf
Frodo and Boromir
Merry and Pippin
Sam
Sam/Frodo
Saruman
Theoden
Wormtongue