I have taken literally 10s of thousands of dollars worth of camera gear with me to Afirca, Equador/ Galapagos, Peru etc. In most of these cases, taking the photos has been the primary reason for the trip. Thus, all the gear, and the priority on it being there when I need it. If you just want to bring along a camera for a vacation, this means differing priorities, so take that into account when understanding my methodology.
Step 1: The Camera gear is your carry on. Period.
Step 2: The CF cards are always on me. (in a smooth sided card case in a cargo short pocket etc)
Step 3: Check everything else.
- I pack my photo gear in a $60.00 "Wenger" Swiss Army (RED) rolling carry on bag that fits in an overhead compartment. This helps prevent it from being mistaken for anything of value, or being weighed. My name and address is written on the bag in permanent marker.
Within this "bag" I can pack:
- my 500mm f/4L IS more safely than most "camera bags" by strapping it to the rails that hold the collapsible handle of the rolling bag.
- At least two bodies, historically two 1D, but now it's a 1D4 and a 5D3, and one more XXD/XXXD sized body like my IR converted Xti
- The 100-400mm always comes with me, along with my 135mm f/2L. The 17-40mm is pretty regular traveler, and in the past the 70-200mm f/2.8L IS, but I've since done away with it in favor of smaller primes. 24-70 f/2.8L has always been included.
- All of the above is "padded" generously in my soft clothing, socks, boxers, t-shirts.
- Whatever sun block I can legally get away with. (first time I did this trick my checked bag was "lost" for 2 days and I was in Africa for a few days desperately hunting for sunblock!)
I have in the past checked some of the batteries and chargers if I could not fit or handle the weight in the carry on. The old 1D and 1D2 charger was one of the most ludicrously heavy accessories ever devised, so this was in fact logical. Make this call based on weight, size, fit and how long you will be in one place if your checked bag were to be late. Needless to say, the size of the chargers for most normal cameras now is such that it's easy to include in the carry on. It's only the 1D series that could still cause one to have to face this dilemma.
Bottom line: Consider your checked bag totally expendable. I've never not able to get one back, but the number of times it has been delayed actually comes close to out numbering the number of times it's arrived on time, and once, I was home before it was recovered.
If such a loss should occur, you can usually by new clothes and other things in other countries with out too much problem. Your camera gear, not so much.
Plus, if you use my method, instead of lugging along a bunch of useless "Tamrack padding" and other heavy crap, you have at least a full set of clothes padding your gear.