I took my camera during this year's Goofy marathon, since I was injured and knew I would stop for photos. It's a little point and shoot Canon. I run with Nathan hydration belt that has a little pocket (an oldy but a goody) and I just stuffed it in there. I should say that I ALWAYS run 1/2's or longer with a belt because that is part of my fuel/hydration race strategy. A phone camera would work fine, too. The CM will work with what you have.
What you use during the race will depend on your fuel/liquid strategy. If you don't plan to run with water or fuel, there are other options--Spibelts are one example, using a hydration belt without the bottles is another. Some people run in shorts or skirts that have pockets--you could do that as well.
Whatever you do, make sure you try it out beforehand. You want to make sure you're comfortable with it.
Maura