I don't have advice so much as commiseration, as I find myself in a somewhat similar situation with my two year old (also born 8/07). She's still in her crib, which I'd like to keep her in as long as possible as it makes things MUCH easier/safer for me. She climbed out once but we talked about it and agreed that she could get hurt doing that and when she wants out she is to call for Mommy or whoever is watching her and they will come get her. That's working for us so far, plus we have a video monitor so we can easily see when she wants out but she's very happy playing in her crib for up to an hour after she wakes.
Anyway, she has mostly been a great sleeper, we would have bath, stories & a bottle on my lap, then I'd put her in her crib and leave and she'd fall asleep.
Up until the last week in July, suddenly she was hysterical if I tried to leave the room. Mommy stay! Mommy sit on the chair! Mommy stay by the crib! So I've been sitting in the glider in her room and leaving after she falls asleep. It can take awhile, and sometimes when I get up she shoots straight up.
However, she's fine with my nanny - she can still put her in for her nap, and she's much better with her Daddy & Grandma, so you might try letting someone else do the caring if you can. Apparently, the Momma can never leave the room. I work during the day so someone else always puts her in for her naps and she's usually fine. Do you have trouble at nap time as well? When my little one gets up at night these days I send my husband in as I will never be able to leave but somehow he can sooth her and leave and she's fine.
ANyway, if you want to have an off-line conversation please feel free to email me so we can commiserate. I am hoping it's a phase. I do not believe in crying it out for us though I realize lots of people like it.
Best of luck!