S.M.
We had the same problem and I felt like a failure too! Keira is our first and she is turning 2 this week. It was hard to hear her cry so we gave in to everything for the first 18 months until I started feeling like a bad parent. First I switched to the soft nuby sippy at bed time which took a few nights to getused to. She was pretty mad for a while which really hurts to hear but it only lasted a 4-5 nights and then she was ok with the sippy. Now we are weaning her off a sippy which has been easier. She will sometimes wake up and want her sippy and then we give it to her (so we can get back to bed) but most of the time she goes right to sleep. Sometimes she cries for 10 minutes, but it is just a tired cry. I have realized that you have to just let them cry which has been a hard lesson for me. We are expecting our second in Feb 2008 and I am determined to change some of the things that I did with Keira. Another thing that worked for us was to give her a cup of milk before bed. Also if she is really crying...let her cry for 10 min then go in and lay her back down for 15 min...if she is still crying then we usually got her up, but 9 times out of 10 she went to sleep. It works, but it is hard on us mommies and even harder on dad!
Good luck!