I bought another DSLR, identical to my current one. One of the criteria for buying this model in the first place was it was the most durably constructed DSLR in its price rage at the time that I bought it because I knew it would be getting some abuse during my adventures in night-club photography. But while it may be durable, it is not indestructible. Not having a decent backup camera started bugging me when I drove to Washington for agentdanak
's wedding. It's one thing to have the camera fail for a local shoot I can reschedule or a club night that where I just miss out on selling a few prints. Weddings can't be rescheduled. And with a car rental and several hours driving involved an equipment failure would have meant not only a very disappointed client, but I'd be out a few hundred dollars and a day's time. I had my film SLR for a backup (and still have several rolls of film in the fridge) but I wasn't entirely comfortable with that since while my SLR is a fine camera, it's old (42 years) and has no automatic settings and the light-meter died twenty years ago. I would have managed, but I certainly would have missed shots. Now I have true redundancy. Because it is the same exact camera body every accessory can be moved from one camera to the other.
Having a redundant camera also means I can send one off for service without being out of commission while the it's in the shop.
In addition to the redundant camera body I've also picked up a match for my 14-45 mm lens, partly for the sake of a backup, but also for stereo photography. With two identical cameras with identical lenses and the remote control that will trigger them both I should be able to do some interesting stereo work. The timing won't be as precise as my White Stereo Realist, and the Stereo Realist is much more compact than two full-sized SLRs so I'll continue to use it out-and-about, but the two-camera setup will be great for studio work and has the advantage of being digital.
Next on the wish-list is stepping up to full 35 mm frame DLSR like a Canon EOS 5D.