We got ours from baby T at exactly one month, too! : ) Only had a few more since, but man is it rewarding after all of these weeks of nurse, spit, poop, nurse, repeat to see that smile! It is as though their little faces explode into a grin. So cute!!
i swear DS smiled at me a few days ago, a little over 3 weeks but he didn't do it again till this morning. DP was holding him and got him to smile a few times. so sweet! he will be a month old tomorrow (yikes!!)