I agree, never leave your memory cards with anyone! better yet, get a cheap netbook, and bring the usb cable for your digital camera, and upload them to your netbook. this way, you have a way to backup your memory card every night. I do that.
Also, make sure to always keep your digicam on you. My brother's was stolen from his luggage and all his photos from his trip with his wife to St Thomas are gone. My digicam is always in my slim, flat over the shoulder bag, I'd never pack it in a suitcase or even a carry on.