I've now encountered this probelm and am looking for advice.
Ds (2 1/2)is making the transition from a cot to a bed - still not complete. Thursday and Friday nights after numerous false attempts (ie ds coming out of his bedroom all excited), we ended up putting him back into his cot. Saturday night, we hooked some stretchies to the handle of the door and onto the hall cupboard, so he could only open the door an inch or two. After one attempt at coming out, we didn't hear any more, so we thought we'd cracked it - but when we went into his room to check, we found that he's climbed INTO his cot, and was sleeping under all the soft toys (including a giant hippo!) that we had piled in there to get them off the floor. Sunday night he stayed at his grandparents, so was in the travel cot.
Monday night, we used the stretchies again, and he did go to sleep on his bed, with no attempts, as far as we could tell, at trying to get out. Last night, he did try three or four times, but then silence. When I went in 45 minutes later, I couldn't find him anywhere - not in the cot, not in the bed..... eventually I found him fast asleep UNDER the bed! I left him for a bit, until I was sure he was sound asleep and then put him into the bed.
So, the stretchies technique (a variation of the "Toddler Taming" rope trick) seems to be working - some may not approve, but he doesn't seem to be distressed by it (and beleive me, he would let us know if he was!).
My problem is ths: yesterday he came running through to our bed at 6.15 am, full of life and expecting us to entertain him. This morning (so dh tells me), it was 4.54 (I was trying not to open my eyes!). Normally we get him up at 7 - although we knew he was often awake earlier - but was always happy to play with the (many!) toys in his cot. His is definitely his father's son (dh is a morning person - I am NOT!)
How do we discourage him from coming though this early? We do try to tell him it is still "sleepy" time, but it only works for a few minutes while he "pretends" to sleep. Do we put the stretchies back on to the door handle (we'd been taking them off once he was asleep), so that he can't get out? Do we take him back through to his room when he comes through before a certain time? A stair gate on the door is no good, as he's be able to climb over it.
Or do I just have to start going to bed earlier to cope?!
My best friend last night on the phone "sympathised" by saying "welcome to the real world - you've had it easy for the past 2 1/2 years!".