I'm sure you'll get a lot of feedback, and here is mine:
For larger amounts of cash, credit cards, passport - I would not leave home without a Money Belt. This is the type you wear under your clothes. You can get one at a travel store or on the rick Steves website. I would NEVER EVER leave this anywhere. I take along a ziplock plastic bag and carry this INTO the shower with me.
For today's cash: A small purse or wallet. I do not keep this in a pocket because there are, unfortunately, pickpockets in the large cities. I keep it in a fanny pack that I wear in FRONT (always!) so nobody can access it except myself.
Camera and other valuables go into the fanny pack in front of me so I can see it at all times.
I would caution you to never, ever ever put your cash, credit cards, passport in your backpack.
It's fairly safe to leave your backpack in your albergue as long as you do not leave valuables in it.
Most pilgrims are trustworthy and few would steal, but there is the occasional problem, so why tempt fate?
If you have never seen a pickpocket in action, you may want to take a look at my latest blog, then watch the videos on the thieves who are roaming the large cities of Europe in the last few years.
Granted, there will be much less crime on the Camino. I know personally of 3 people who had their cash stolen by a "helpful" pilgrim while they showered. But in the larger cities, take cautions and seeing the video will make a believer of you in addition to simply educating you.
My blog link:
http://caminosantiago2.blogspot.com/