Hi there,
I totally understand where you're coming from- the only thing that worked for my 23 month old son and 3 month old daughter was to let them cry it out. I waited until my son was a year old (I was pregnant again- that was my motivation!!) to cry it out and I am a believer, so much so that I've already started with my daughter and she is almost sleeping straight through the night at 3 months old. When we did it with my son, I would let him cry for 15 minutes and I would go in there (his crib in his room) and try to calm him... but that would usually make it last longer. With him, I just let him cry (in the beginning it sounds horrible- like they are screaming... but it IS ONLY TEMPORARY... they WILL GO TO SLEEP) sometimes they might even stop for a minute and start back up again and my son had a tendency to throw up when he cried... He would stand up by the side of the crib and throw up over the side onto the floor- so I put a towel down and that caught it. I know that sounds REALLY HORRIBLE... but it was worth it. He would cry like that for about 20-30 minutes for about 2-3 weeks and then it gradually got shorter and shorter- like just 5 minutes and then we got to the point about a month after starting where we would just say.."It's time for bed Sam, where's your bed?" and he would walk back to his room, right up to his crib and want in bed- and we would put him in and he would just lay right down and go to sleep. If he cried at all, he would maybe just whimper a little bit and then be right off to sleep for about 11 hours. Sometimes, he would cry in the middle of the night and we would just leave him and he would go right back to sleep. I would make exceptions and go in there when he was sick, if there was a thunderstorm or loud noise that woke him up.. but a lot of times he would cry out in the middle of the bed, if I jumped out of bed and went in there he would usually be asleep and crying in his sleep.. they tend to cry when the sleep cycle changes.
I know this sounds tough, but it was the answer for us and knowing that I was going to have another baby when he was 20 months old, I knew I had to get his sleep under control. Plus it makes it harder when they get older and can climb out of bed or cry out "mama"- the older they get the longer they can cry :) I've discovered that with my 3 month old. She doesn't cry very long at all and the whole process has been easier with her.
I have a friend who has a son the same age as my son and he still nurses ALL NIGHT LONG and they even had to move his crib into their room and when he wakes up in the night he has to be put in bed with them. I think it's really hard on their marriage and she is considering not having any more children b/c he's almost 2 years old and still acting the same way as a newborn- but he can talk now and tell them what he wants. Sleeping is a developmental stage but it also is a habit, and I really believe that you have to train them to create that habit.
When we did this with my son it was right around the time that I weaned him from breast and bottle and that worked well... but the sooner you do it the better.
A couple of books that I HIGHLY RECOMMEND are: Sleep Sense (http://www.sleepsense.net/sleepinfo.html ), Baby Whisperer, BabyWise is good- but it's really to0 strict for my liking- I found it was the best to combine ideas from different books and adapt them to what I knew about my own child.
You definitely know the best of anyone what's best for your child, but I am just telling you what worked for me and it REALLY WORKED! It's harder than you think it will be, but you HAVE to be consistent or it won't work. And both you and your spouse have to agree- because there's nothing harder than you finally working up the resolve to do it, and a few days into it, after 15-20 minutes has passed of hearing your baby cry.. and one of you gets emotional and starts to question the method and the other one of you feels guilty... It's not hurting your child to do this, it's training them how to sleep... and it really does work. I think it's one of those "tough love" things :)
Hope that helps,
E.