lol my son did this too, sometimes still does! but usually only if he doesnt want to eat that particular food.
sometimes when he goes through a teething spell he only wants really crunchy textured foods and avoids anything 'smooth' (more so when he was about the age of your baby)
i wish i could remember what age, but at some point my DS (now 20 months) also started wanting to feed himself and would NOT eat if we fed him - had to be his own spoon/spork! (we found that the 'the first years' sporks were much easier than a spoon since he could spear food and it wouldnt fall off). This was usually at the begnning of the meal and then he would be ok with us feeding him while he held onto the spoon/spork
whats really funny is giving them something new that they dont like - and then they get this look on their face and (at least my DS) just opens his mouth and lets the food fall out into my hand! i am just happy he tries it, this compeltely grosses out my DH so maybe thats why i think it's funny LOL