Separation anxiety is here! Yikes! I'm very well aware of separation anxiety; I've learned a ton about it in school as well as talked to many parents on this phenomenon but, wow! They really do cry - no, wail - almost every time you leave the room, go around the corner or even duck behind furniture. It's tough!
I warned my husband that this would happen around nine months of age. He understands why it happens but still feels bad, and often takes it personally, when he can't calm our baby himself. It sometimes makes him feel as though he hasn't bonded with our baby. The other day I had to bust out one of my child development textbooks to remind him why no one but myself can calm her down. We read that this is a really scary time for babies as they're just realizing that they are separate from their mothers (or other main caregiver). They don't understand that the mother will come back; they're scared that they're never going to see them again. It's a very healthy and normal step towards the development of their independance. Since I had him read about separation anxiety, he has started to bring her right to me the moment she starts to get anxious. On the flip side, once she is relaxed and playful, I'll bring her right back to him so they can have their father daughter time :) This system has been working very well for us.
With other people however, I've become quite protective of my baby while she's going through this critical stage. Normally I'm shy and non-confrontational but, I've really learned to suck it up and stand up for her. Before I let anyone hold her, I will let them know that she's experiencing separation anxiety and if she cries I'm going to take her back. Then if she does wail, I shamelessly yank her right back. Most people are OK with this but I've gotten a couple, "oh mom, go sit down, she'll be fine." In that case I just continue with the yank maneuver and say, "I'm going to take her, I'll bring her back when she's calmed down." Many want to calm her themselves but let's face it, they can't. Nor do I want them to. Especially for this, the reason behind the cry is just too important.