ok Time for my two cents... (I love this stuff)
As for all hobbits being equal size: All five actors (that's counting Ian Holm as Bilbo) are 5 ft. 6 in. tall or real close to that. John Rhys-Davies is just over 6 feet (I believe 6' 1"). If the special effects tweaked the visuals, which they did, all five hobbits would still appear the same height while the dwarf would be taller. Kath, you made a good point there. However, height even varies among little people, I think the reason Chocolate factory oompa-loompas (gosh did I spell that right?) or munchkins from OZ are of various hights has to do with varying heights among the actors.
Sadly, I have to agree with some of you on the portrayal of Frodo. When he dropped his sword and ran from the nazgul on weathertop was bad enough (in the book he stabs the witch-king) but driving Sam away and believeing Gollum is just this sweet, honest, harmless poor victimized creature was AWFUL. And there was just one too many Frodo-with-Ring-in-hand-staring-into-space-shots.
It is my opinion that one the great travesties of the movies was the portrayal of Elrond. They took noble, venerable, wise, sympathetic, kind as summer and turned it into Ticked off at everyone-don't bug me I have jealously issues-men are so stupid and so are dwarves and hobbits. Ai! As for the rest of the elves, physically they were well done. They are supposed to be beautiful and ethereal ,and that came through quite well. But they were tooooo serious! What happened to "merry as children?" All the movie elves' heads would have imploded after ten minutes in the hall of fire. They only time they ever sing anything they are lamenting. Haldir was way too standoff-ish (But if I was shoved where I wasn't supposed to be and was told to die I'd probably be in a bad mood too). Granted, in the book Haldir is a bit crabby at first but he ends up becoming good friends with all the members of the fellowship. And of course, poor Celeborn......
And Legolas was just a little too superheroy