Yeah, I just did an 18 month update, but Liam is 19 months already (actually 2 weeks ago).  So short update:

• Has kinda started pulling himself up onto his knees from a sitting position.  Got an owie on his chin from falling into coffee table doing this.
• More signs: please, thank you, potato, car, swim.  That brings his total signs to 21 (I think).
• Is putting signs together to make short sentences: “more milk please” is the most common with “please” actually being verbalized.  Nonsensical sentences made as well like “ball book baby bear” or “baby milk book”.  Got no clue on what he’s trying to say.
• Actual words: yes, book, please, and hi.  He will imitate other words but doesn’t use them on his own (kitty and cheese are the two most commonly imitated words).
• Block stacking has progressed to 4 block high towers if and only if he has one block to choose from.  Give him a pile of blocks and it’s a free for all throwing session.
• No more baby food.  At all.  Last night’s dinner was green beans, garlic hash browns, and applesauce.  He has no troubles with food except for meats.  He spits out most every meat we give him unless it’s mostly pureed.  We’re working on stopping that.  Over the past few weeks, he’s eaten ravioli w/ marinara, mixed veggies, corn, peas, sloppy joes, French toast, tacos, Buffalo chicken fingers, hamburger w/ mustard, peaches, watermelon, brownie sundaes.  We don’t make bland food for him either.  He eats what we eat.
• Is making animal sounds.  Meows at the cats.  Meows at dogs, meows at cows.  He did learn how to moo, but once he learned to meow, every animal says “meow” now.
• Points to objects.  It’s not a true point with just the pointer finger, but it’s pretty obvious what he’s doing.
• Is starting to scribble with crayons and markers and actually has an interest in doing so.

What else I’ve noticed: When we were in New York, Liam was around his cousin who is 3 months younger than him.  Other than the walking thing and some better self-feeding skills by his cousin, there wasn’t one iota of difference other than personality.  They’ve got the same little toddler quirks, same social skills (I’m willing to say that Liam is higher functioning here), same communication skills (again, I’ll say Liam is higher functioning here too because of the signs).  It was pretty amazing to see.