Izzy started waking up to play around the time we started solids. She didn't make a peep until she started to get frustrated that she couldn't crawl as eficiently as she would like and by the time that happened, she was already so wired that it was difficult to put her back to sleep. We tried just letting her play, but she would end up needing help getting back to sleep. We tried bouncing, rocking, walking, singing, swinging, etc, but it seemed that all of that just served to stimulate her even more and keep her awake even longer.
This week, we've had miraculous success *knock on wood*. We will hear her bustle about, and DH will go to her (as not to confuse her with The Milk Lady) and gently lie her back down again and wrap his arms around her while she's still lying in the crib and shhhh her until she's relaxed and still, then he lets her fall asleep on her own. If she starts to play and crawl again, he does the same thing over and over and each night it's been less. Last night - dare I say, was the first night she just slept - for 7 solid hours! I was so happy I was ready to bake her a cake and buy her a pony.
We'll see how tonight goes.