As I mentioned in the Air Show Pictures and Photography Tips
, a high-mileage 1Ds Mark III was DOA at a distant event I was attending. Had I not taken a second camera, I would have no pictures from my 10 travel hour trip.
If you do not have a second camera body and lenses (or third if you shoot with two at a time), give consideration to buying or renting them for your next big event/vacation. And if renting, remember that summer is the busy season for the photography gear rental season. Roger at LensRentals.com recently noted on his site that reservations are an important step to insure you get the gear you want when you want it.
Summer vacations are often a great time to try out that new piece of gear you've been eyeing up. New gear adds fun to an already fun time.