Excellent suggestion! I find I use my cell phone camera more and more as a back up brain. I take pictures of the list of pre-reserved sites posted at the campground entrance so we know which ones are available as we drive through, the cost of the different sites so we know what to fill in on the little envelopes, schedules at museums, parking lot signs so we can find the car again, etc. etc. etc. We also take pics of the informational signs along trails and and parks so we can reference them when we post something on the blog. Our memories cannot be trusted to get that stuff right, even if we think we'll never forget it. The wiring of the batteries is a an extremely important thing to get right and an excellent use of the "back up brain" photo method.