Update

At his doctor's appointment two days ago, he was:

25.3 lbs (50th percentile)
32.5 inches (90th percentile -- tall boy!)

He is becoming more and more sophisticated and is having a language explosion, repeating almost everything after us. He also now says, "No!" and has a verb: "Go!" (used when sitting in stroller, waiting for Mama to get everything together for a trip to the park). He now uses words to express his concerns and desires rather than just crying. He has also started calling for me in the mornings ("Mama!" rather than "Waaah!), and he has a consistent word for nursing ("Neee"). He says "Hi" and "Bye" and waves, and he has many admirers in the playground and on the street.