I am sitting here watching my 2 year old have a melt down over a blanket. It was laid flat for Caelyn to use for tummy time and it shifted, so Ethan was trying to straighten and make it perfect. Of course it keeps shifting as he pulls different spots and he just breaks into tears!
He does the same thing with puzzles and toys, lining them up in a perfect line and freaking out when they shift out of place or we move one.  He was screened at 18 months for disabilities cause he wasn't talking, but he was cleared as fine and now talks in sentences.  He's very smart and counts to 20, knows his letters and colors and loads of other things and is very social with adults and other children. Can little ones be OCD this young or is this just a normal toddler behavior?  I always thought little kids like to throw things all over the place, not want to clean it up all the time. 
Re: OCD Toddler?
My DD#1 is very flexible in some ways and very "OCD" in others. When she was closer to 2 it was worse- tapping food before she ate it, Walking in such a way that the bows on her shoes dodn't bounce to the other side. If she had 3 balls, and one of the babies found a forth, she would freak and try to get it, but sooner give her 3 to the baby so all the balls were together. I was OCD as an older child so my radar was very intense, but she is growing out of it. She still has some "isms" but oddly, I've spoken with her teacher and she now counsels other children who worry about such things "It's okay! Sometimes the firetruck ladder is up, and sometimes it's down. It's no big deal!" and doesn't display any rigidity at school. She saves it all up for me.
I am guessing it's normal and most grow out of it.
DS has to know where certain toys are at all times and if one is missing from the order he's put them in it's a complete meltdown. Same with arranging his pillows at night and where precisely on his bed his one blanket needs to be.
He also has to have exactly 3 ice cubes in his drink and specifically a yellow cup.
Like PP said, I think they are more aware of details and that having things being predictable helps them with their daily routines.
nice to hear we aren't the only ones!
violet (01.06.2011) & colt (09.27.08)
expecting surprise baby no.3 may 3rd
I was just telling my friend today that (a) toddlers are really freaking weird, and (b) totally OCD.
Lily melted down the other day because when I came home, I went to her to greet her, THAT'S NOT THE WAY IT'S SUPPOSED TO BE! She had to come running to me. And she had to greet me in in the kitchen. ONLY that way.
And there's nothing worse in the world than a broken cookie. BROKEN! The only way to react to a broken cookie is to flail, scream, and cry. Right?
My silly Lily is almost 4.