Thank you for all the advice, ladies! I talked to Eli's pedi last week and she said that it is absolutely up to us when we want to start. Her reasoning for starting him on cereal/solids now is recent research on food allergies. The newest line of thought is starting earlier and introducing certain allergens early on may actually prevent some food allergies. (There was a big study in Israel where peanut butter was introduced at a very early age, leading to virtually no peanut allergies in the study.) Anyway, since some studies also say waiting can help prevent food allergies, she suggested starting solids at 5 months instead of at 4 or 6 months. We will see how Eli does in a month, but I'm relieved to know she was an advocate for letting us make the decision.