QUOTE (MeeksDigital @ October 7 2008, 03:06 PM)

Rent a Canon 1D series body.... they're weather sealed

OMG! Haha... Yep, could very well be needed.

Honestly, Kate, making a birth "pretty" is quite as feat. Pretty it is not. But giving your friend special images that she will treasure, you betcha!
I echo Rees' suggestion to ask your friend if she prefers that you not use flash. If she doesn't care, great! But be prepared to discontinue the use of your flash if she does become annoyed by it. I did not use flash for the births I've shot; I just shot at higher ISOs. Hospital rooms don't usually have the best light, but when it comes time to deliver, they do usually turn on a very bright light right over mom's bed. So bright, in fact, that it leaves pretty deep shadows in areas beyond the bed.
Certainly you need to be prepared for what could be a long day/night. You might arrange it so that your friend calls you up to the hospital once they know for certain she is in active labor (of course, active labor can be loooong). Pack some snacks and then head up there prepared to hang out and document things as they happen. Look for those sweet moments between friend and friend's hubby (and other family memebers friends) as they comfort/encourage her. Look for the details such as the baby moniter strapped to her tummy, the machine recording babies' heartbeats and her contractions, the itty bitty outfits waiting for their new owners to wear them home, etc.
Oh, and it gets quite busy down at the end of the bed once baby (babies!) actually emerge, so if you want a good shot of the new little ones as they hold them up and possibly place them on mom's tummy, I've found that it's generally best to stand up by mom's head.
I do have one birth story posted on my website at
www.melanieswanphoto.com It is the last of my galleries, labeled "The Allens." You're welcome to check it out.
Good luck!