A couple of American girlfriends have mentioned something called a "crib tent" which is designed to help keep them in the cot/crib for a little longer! I haven't seen one in HK but it may be worth investigating.
I think the crib tents from the US/Canada will probably only be of any use if you have a North American sized crib as they fasten to the sides and rise up like a tent, but most of us in Hong Kong won't have that size of crib as it's not commonly available here.
