I too make a copy of all my documents, includes my ID, Passport and all my credit cards. I leave one at home (for the house sitter), one with my parents (in case I can't get a hold of the house sitter), and I bring one. I include in the documents phone numbers of all of the contacts (visa/MC), including the nearest Canadian Consulate (a little overkill, but when you lose your passport or if it gets stolen, this is a godsend!).
I also agree with the ziplock bags...I LOVE these things for travelling...you just never know when you will need them. And usually, I use every single one I travel with by the end.
Travel size of sun screen for the parks. And a sunscreen lotion for my face...I get a small container from sephora and bring that into the park with me instead of spraying a screen on my face, I can just apply a dab of a sun screen meant for a face (the mixture of oil based products and the heat = break out for me!).
I also agree with the medicines. Nothing sucks more than having to find meds when you are travelling. I bring a pretty good first aid kit too...again, you never know when you are going to need it, and I have used something from it the last 2 trips we have taken. Short of reseting a bone and/or stitches, I can pretty much do small medical miracles with my first aid kit, and truly, it isn't that big (I am a nurse though, so I do have some experience with medical issues). I leave it in the car when we are in the parks (they have first aid stations for a reason), but I do bring in collapsable scissors, moleskin and bandaids into the parks.
We should start of list of things we won't pack again as they were a waste of space!