I do modified CC, I call it "whinge it out" rather than cry it out. I let DS whinge and carry on like a pork chop when I think its necessary, but if he gets into serious crying or what I call a "state" then I get him up, calm him down and we try again. My reasoning behind this is that once he crosses a certain line, even if he did fall asleep, he hasn't actually learned to settle himself. He's only worn himself out from bawling and/or given up, neither of which really get you anywhere. But as long as he's just whinging or mildly crying, I will let him go if its a habit I really need to break (like waking at midnight for no real reason, grr). Only you can know where the line is for you and your LO- what constitutes whinging and what constitutes serious crying.

This method has worked for us so far, although it may well not work for everyone or work for us forever- I dread the day when Peter realises all he has to do is really cry in order for him to get up!

If you are looking for different methods, Elizabeth Pantly's "No Cry Sleep Solution" is supposed to be awesome.