i'm late on this thread but here is mine;

DS4 - lots of little things that made me think 'ohh that was odd'.
My real clincher was; When at 2yr 8m(ish) we were out and he was in the pushchair in a shopping center and said 'oh thats silly Thomas is a train he can't cook!'. I'm looking around like a fool trying to see what i thought was a cooking book....then i saw it - Thomas Cook - a Travel agent.

DD<2 - She has this look that you can see she is seriously pondering things. I don't know definitely (i think she is way too young to even think about it) But she does things that are very calculated. She counts 1-10 already, and she draws proper tadpole people.