My 20 month old DD can definitely settle herself to sleep. We put her in when she's tired, and she can fall asleep on her own with no problems.
BUT - lately she's been laughing in her crib and babbling a lot (she's not really talking yet, I have a whole other thread on that issue, maybe the babbling is her "practicing"?? Its very recent and its combined with increased babbling during the day). The babbling I think I've heard about, but all of a sudden we'll hear her hysterical laughing. Its kind of strange and I can't lie...a little disturbing. What could possibly be so funny in her crib in the dark?? Has anyone ever heard of this?? Its usually on and off for a few minutes then she falls asleep until morning.