None of my children have ever slept a night in a crib. I don't even know how its done. Whenever I put them in there, they wake up immediately.
We co-sleep until about 1 year old and then move them to a toddler bed. It seems easier that way, but maybe I'm doing it all wrong.
Anyway, since our crib doesn't get any use, I turned it into a ball pit. I got these balls for free at my mom club clothing/toy swap: