We tried some rice cereal last week. I had wanted to wait on solids until Terran was closer to six months, but it seemed like he wasn't staying full and was interested in eating. The doctor said it may be better to start earlier with him as well since he was still waking in the night and is a big boy.
He wasn't too enthused in the beginning.
I have since fed him twice more, with the last time making him a little constipated. He seems to be satisfied just on breastmilk again though, so I am going to keep waiting a little while longer before making this a daily thing.