I watched the commentaries last night and one of the most interesting things was when they talked about the TARDIS internal set. Apparently the guy who created it didn't want to do it and did it all at the last minute - which is pretty impressive when you consider just how much of that original design has lasted right up until now! He came up with the idea for basing it all on hexagons - the hexagonal console and the round/hexagon-shapes on the walls.
( Cut for length )
( Cut for length )