My oldest DD was a couple of weeks shy of 3. She had just started being "unhappy" in her crib, and then we moved to a new house, and DD number two was due in three months. She did fine with all of the transitions. DD #2 will be 3 in December and is still in the crib. She loves it there. She does know how to get out of it, as she has climbed in and out a few times during the day. But for naps and at bed time she never gets out until we go in and get her out. My mother didn't give me a lot of parenting advice, but one of the few things she DID tell me was.."keep them in a crib for as long as possible!" (within reason, of course!!). They are safe and secure in a crib, and we don't have to play the "get out of bed, get in bed, get out of bed, get in bed" game yet!