Hilary Duff's son Luca is the center of attention in a new picture she posted on Twitter. The little guy entered the world three weeks ago on March 20, and last week, we saw the first pictures of Luca Cruz Comrie. Hilary has been spending lots of time with her son, but also stepped out not long after his arrival to visit her salon and even the gym. She's shared all sorts of sweet sentiments about motherhood. Last week, she mused, "No better feeling that a peaceful baby sleeping on your chest. . . wonder what he's dreaming about?" The love continued yesterday when Hilary tweeted, "Almost home to feed my little bambino! Nice to get away for an hour to do something good for myself, but I miss his little face when I'm gone."