Hey:
I took a Canon A570IS camera on the Camino during July and August of 2007. I bought it because it was light, had good reviews on Amazon, and ran on 2 AA batteries. It was a good choice - took great pictures and was easy to use.
As for batteries, I brought along 8 AA Energizer Lithiums. A photographer friend recommended that I buy them, and he was right. I was expecting I'd have to change batteries every 2 weeks or so, but that wasn't the case. After 30 days, the Canon was still going strong but I went ahead and changed the batteries anyway just to be safe. Heck, I even gave away 2 of the Energizers to a Spanish guy for his camera
Frankly, I'd go with a small AA-powered camera. Sometimes the plug-ins at albergues are limited, and you'll have to compete with other folks using them to charge cell phones and such. I took almost 900 pictures (used one 2GB SD card - had a spare, but didn't use it), and the Canon and Energizers never let me down. You can find AAs along the way, but as you can see from my experience, if you bring the right ones you won't need to buy any.
As an FYI, I used an M-Rock Yosemite case for the Canon A570IS. It was an excellent little case - the camera fit snugly, so I didn't have to worry about it slipping out. The case also came with a neck strap and weather cover, and it had a thick velcro strap on the back which I used to attach it to my pack's waistbelt. And its pockets held 2 batteries and the extra SD card with no problem.
Anyway, hope whatever camera you choose serves you well - buen camino!