my older son used to wake every night, like clock work. until he was 2 years old, he'd wake a minimum of once per night.
we discovered that because we were sitting on a chair in his room as he went to sleep, when he woke in the middle of the night, he'd want the same thing.
when the new baby arrived, i just couldn't cope. i had tag-team children on a few nights, it was awful. finally, one night, i'd had enough. i just told him straight that i couldn't do it any more. i was going to my bed to sleep. i made sure he had his toy cars that he likes to sleep with, he had his cup of juice, he had a book (just in case) and i covered him with the blanket.
it took a couple of nights, but he eventually stopped waking up. in the past month, he's only woken up on 2 nights.
it was 2 years coming, but THANK GOD! he's finally doing it. i just think that he was looking for us so that he could go back to sleep in the same conditions as he had originally. when we stopped sitting by the bed, he stopped waking up at night.
my baby, on the other hand, has been a fantastic sleeper.... so far...she's 3 months old today and has been sleeping 7-10 hours at night for the past week and a half. i can only hope that she keeps it up!
good luck everyone, and i hope that YOU get a decent night's sleep in the very near future!