I can't believe i never noticed this til now (over a year since the show debuted!) I've always been a huge Calvin & Hobbes fan. I used to love to read the comic anthologies to my nephews doing different voices for the characters (at one point i thought i may want to someday go into cartoon voices). It just recently hit me that Sid the Science Kid sounds pretty much exactly like i always imagined Calvin would sound like and how i voiced him! It's actually kind of interesting how much they have in common - active imaginations, love of stuffed animals, has a particular toy he's rarely seen without. (Sid's affinity for his microphone with built in applause reminds me of the strips where Calvin goes around with a cardboard cutout frame of a tv set around his face putting on his own television shows or when he approaches his mother in the kitchen: "Bum de de dum dum - Hi Mom - WHAT"S COOKING? Bwa ha ha ha! (I decided my life would be much better with a music score and laugh track)" None of the other characters sound like any of the other voices i always associated with the C&H world. I always did the father with a very stoic Frank Oz businessman type voice - Hobbes was also kind of Frank inspired...one of those gruff type voices - like one of his monsters with a bit more intelligece and refinement than usual) As for Susie Derkins, i can't think of any voice from a Muppet or cartoon character that comes close - i had a very unique voice for her (and she was always my favorite to "do") which went from sweet to hugely and loudly annoyed.