I have two children: A is about to turn three and L is just shy of one. We were lucky enough that A slept through the night at six weeks old. Of course this meant that she slept in bed with us, had to hold our hand to fall asleep and wouldn't sleep by herself. Weaning her into a "big girl bed" was not too difficult, but she still expects you to hold her hand for awhile.
Well, so I thought all babies that I would have would sleep the same. Didn't happen that way! Here we are at almost a year and L won't sleep through the night. I would say seven days (seven glorious, wonderful, marvelous days) he slept for about eleven hours. Those mornings I'd wake up full of energy (I took up jogging) and ready to meet the world head on. Then came the sickness. During the time he was sick and for awhile after he'd wake up many times at night. It turned out that L was allergic to the milk based formula, but after two months of constant trips to the doctor and no answer I tried switching him to soy and voila!- sickness gone. I tried the Ferber method. That lead to him being able to fall asleep quickly on his own, but he still wouldn't sleep through the night. I tried the doctor's suggestion of letting him cry himself back to sleep. After two hours I gave up.
Fast forward to present time. My final solution was to bring L into bed with us. I am at the point where I will do anything that gets me more sleep. So, now instead of waking up four times at night, he wakes up once and I can get him to sleep later in the morning. I've realized that L is a very light, restless sleeper. The slightest noises wake him (he takes after me on that one) and he flops all over the place in his sleep (that he gets from his dad.)
I suppose until a better solution presents itself, it will be this way until he's old enough to comprehend a big boy bed. The title of that blog will be "Hallelujah 2011: A Good Night's Sleep."
Sorry for your lack of sleep!