I'm making one now, along with a friend, for another friend who just had surgery for breast concer and will shortly be undergoing radiation. Basically as we knit we say prayers for her recovery and well-being as we knit. We hope that when she drapes it over her shoulders it will give her comfort, warmth, protection, strength, and let her know that she is loved. This is the first time I'm done it. I'm not really a knitter, but it feels good doing something like this, at a time when you want to help but don't know how.
If anyone is interested, here's a site for more information.