I'm thinking of buying a second camera body.
I'm thinking of either buying a used Nikon D200, like the one I already have, or a new Nikon D300.
I'd love a D700, but it's a little out of my price range right now.
Anyhoo, I was doing a little online reseach about the expected lifetime of my D200's shutter since it already has about 40,000 cycles on it.
Then I came across this video.
Parts of it are a little technical, but I think it will still stand up well.