While people have pointed out that the CrashReporter dialog box may be disabled, this still runs the CrashReporter on each application failure, and writes a crash report to disk. Since it can take a long time to write the report, developers may want to disable crash reports entirely. Here is how.

From within a Terminal.app window, you have to run the following command once: You then have to run the following command every time you log in. (I added it to my ~/.bash_profile file, which is good enough for running tests.) Note that running defaults write com.apple.CrashReporter DialogType none definitely doesn't have the same effect as the above -- it disables the crash dialog, but Crash Reporter still contributes to the heat death of the universe.

If this hint works, you can thank Tim Shead of K3D fame. If not, feel free to clean up the broken pieces.

[robg adds: I haven't tested this one.]