Hey, I don't have this problem yet, but I'm sure I will. I have this amazing book called "you just don't duct tape a baby" the title is based on one of the stories inside. One of the suggestions that's in this book (which is just a funny, calming, book full of information on how kids work) is that, if you can, get a 1/2 door. You know, one that splits in half. That way, the kid is literally confined when you lock the bottom half, but you don't have to feel like a psycho who locks up her kids. It's just a physical boundary, and the rest is up to the kid. Like, you put her down, she's tired, and you let her cry it out. I don't know if you've ever seen Super Nanny, but bedtime routines WORK. Just be consistent, and don't let her control your actions. If you really can't stand letting her cry, then be prepared to not sleep too well.
It usually just takes a couple days, some kids can take longer, up to a week or two...but it's worth it!
Hope this helps,
A.