Cecil Adams should be played by this guy.
Tangent will be played by George Hamilton. 
Actually, Adam Savage would be a decent match.
FXMastermind will be played by The Horned Rabbit, since he is currently at loose ends and the two are nearly indistinguishable…
-XT
And I was going to suggest Katherine Hepburn for you. She certainly has (umm, had) plenty of lip to give.
I hear Lucille Ball wants to be carnut.
Unfortunately I would probably be played by Rosie Perez with Eddie Murphy’s Buckwheat voice dubbed in of course(because compared to Ms. Perez, Buckwheat is downright melodic.)
Actually, that guy should have been played by Cecil Adams.
I’ll be over at Craft Services washing dishes, so I won’t be in the movie. However, any needed voiceovers will be performed by Kermit the Frog.
I will be played by Suge Knight
Skippy’s stunt paws and an accordion.
As so many have been before you. 
I wanna be played by Kari Byron from Mythbusters.
TOmndebb would be Novello playing Guido Sarducci.
Can I borrow your jacket? I need to reskin my tipi.
We thought that was who you are !!!
I don’t think I’m castable, so I would play myself, the way John Wayne did.
Note to TubaDiva: Why don’t you write the music? By itself, it could be a symphony with movements representing the different moods and personalities, and as for the soundtrack, well… make it a cacaphony.
Q
I protest this suggestion for the soundtrack. I don’t have a personality and never have, and I refuse to be represented by silence on-screen.
Maybe I should start a poll on whether you remain silent(on screen, of course.) 
Heeeheee! That makes me happy.
I came in here to say that Skald should be played by Samuel L. Jackson, but not only was I too late, but he (Skald) refutes it. I think he’s wrong, though. Whenever I read a Skald post, I read it in Samuel L. Jackson’s voice.
John Cage for Skald.