I was getting the following message when synchronizing my iPhone with firmware 2.0 to iTunes: "MDCrashReportTool closed unexpectedly". This is cause by a bug in Apple's crash reporting tool which make it crash when retrieving bug reports from the iPhone (pretty ironic ;-)).
To avoid the issue, you can open a Mac OS terminal widow, and type the following command (one line):
sudo chmod a-x /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/Resources/AppleMobileDeviceHelper.app/Contents/Resources/MDCrashReportTool
This simply prevents the tool from running. Note this is a workaround and not a fix, and it will completely disables the bug reporting functionality (but it was crashing anyway ...).